Asking whether Buddhism is still relevant assumes the interesting thing about it is its age — that it's a technology which might have been superseded, like asking whether a filing system from 500 BCE still works. But it isn't making a claim about the world that new instruments could overturn. It's making a claim about what it's like to be a person who wants things, and that hasn't been revised.
So the honest question isn't whether it survived twenty-five centuries. It's narrower: which parts of it still bite, which parts got harder rather than easier, and which parts of the version currently on offer have been quietly hollowed out. Those have different answers.
The diagnosis was never about misery
The first thing that has to go is the translation. Dukkha gets rendered as "suffering," which makes the first noble truth sound like the gloomy assertion that life is bad — a claim most people's lives straightforwardly contradict, which is why it's so easy to dismiss.
The word is closer to unsatisfactoriness. Stress, friction, the quality of not quite sitting right. And the diagnosis isn't that experience is painful; it's that it doesn't stay. Pleasant states end. The thing you wanted, once you have it, becomes the baseline from which you want the next thing. What's identified as the cause is not the world failing to deliver but taṇhā, craving — literally thirst — including, in the canonical analysis, the craving for things to be otherwise and the craving not to exist at all.
That's a claim about a mechanism, and it's testable in the only place it operates. It's also, awkwardly, a much better description of an affluent life than a deprived one. A person short of food has a problem; they do not have this problem. This one shows up most clearly when the obvious needs are met and the restlessness carries on regardless — which is roughly the condition a large part of the modern world has arranged for itself, and roughly the condition of a man who left three palaces at twenty-nine because having everything turned out not to settle it.
The part that got harder
Most of the tradition addresses a situation that hasn't changed. One part addresses a situation that has changed dramatically, and not in our favour.
Attention is now a commercial input. Not metaphorically — a substantial share of the world's most valuable companies are funded by holding it, and the systems doing the holding are tested against millions of people continuously and improved on the results. Nothing in the fifth century BCE was engineered to capture a mind. Whatever pulled a monk off the breath back then was, at worst, an unusually loud bird.
So a training whose first move is to place attention somewhere deliberately and notice the instant it's gone lands differently now than it did then. It isn't that Ānāpānasati has become more true. It's that the ordinary condition it works against has an industry behind it, and the skill of noticing you've been pulled — not resisting the pull, just seeing it happen — has gone from useful to something closer to load-bearing.
I'd put the epistemology in the same bracket. The Kālāma Sutta is a set of instructions for what to do when confident, mutually contradictory claims arrive from people who all sound authoritative. That was a description of a town on a trade route with a lot of passing teachers. It is now a description of an average Tuesday.
And it holds up better than its reputation, because it doesn't do the thing it gets quoted for. It doesn't say trust yourself — your own reasoning and inference are explicitly on the list of things not to lean on, alongside tradition and authority. What it offers instead is a test based on what a quality does when you take it up: whether it leads toward harm or away from it. That's a criterion I'd struggle to improve on for an information environment where verifying claims directly is mostly not available to me.
Where the modern version goes wrong
Here's the part I'd want in any honest answer, because the thing usually recommended as relevant is not quite the thing.
Mindfulness has been extracted from all of this and sold back as a stress-management technique — an app, a workplace programme, something to make a difficult job tolerable and an employee more productive. The techniques are real and the benefits aren't nothing. But in the tradition, mindfulness never stood alone.
The training is presented in three parts and an order: sīla, ethical conduct; samādhi, mental cultivation; paññā, wisdom. In the eightfold path the same structure appears as right speech, action and livelihood sitting before right mindfulness. Not because ethics is a moral entry fee, but for a practical reason: a mind carrying regret, or spending its days on work it has to avoid thinking about clearly, is not a mind that settles. The ethics is load-bearing for the concentration.
(The relationship is more spiral than strictly linear — the path list opens with right view, which belongs to wisdom, so each part keeps feeding the others. But sīla is consistently placed before samādhi in the training, and that placement is doing work.)
Which makes the popular version a strange inversion. A practice developed by people who renounced almost everything, aimed at seeing through craving, now widely marketed as a way to keep going in an arrangement built on producing it. That isn't an argument against using breathing exercises to calm down. It's a reason not to mistake that for the thing, and not to conclude the thing has been tried when the ethical half was never picked up.
The parts that don't translate easily
I'd rather not do the move where everything inconvenient is quietly reinterpreted as metaphor.
Rebirth and kamma are load-bearing in the Theravāda texts, not decorative. They aren't straightforwardly compatible with a modern materialist picture, and the versions that reduce them to "actions have consequences" and "you're a different person each morning" are doing something to the source material rather than reporting it. I don't have this resolved. I've written elsewhere about the Pāyāsi Sutta, which takes a materialist's experiments seriously enough to argue with them properly, and I found it clarifying without finding it conclusive.
What I'd note is that the tradition anticipated the problem. The same Kālāma Sutta ends with a passage aimed exactly at someone who can't settle the question: whichever way it turns out — hereafter or no hereafter, results of action or no results — a mind free of hostility and ill will is not worse off. That's offered as a reason to proceed without first securing metaphysical certainty, which is a more workable position than either demanding belief or pretending the claims were never made.
The other thing I'd resist is the flattering comparison — Buddhism as "basically science," compatible all along, vindicated by neuroimaging. It's flattering to both and fair to neither. A tradition aimed at the ending of craving and a method aimed at modelling the physical world are not doing the same job, and the overlap gets oversold by people who want the prestige of one for the other.
So: relevant to what
If the test is whether it makes modern life more comfortable, the answer is mixed, and the tradition would be a strange choice — its founder's response to a comfortable life was to leave.
If the test is whether the diagnosis still describes something real, I think it plainly does, and describes the affluent version of the problem better than most things aimed at it. If the test is whether the training addresses a condition that has got worse, the attention part is hard to argue with. And if the test is whether it asks to be taken on faith, it asks less than nearly anything else making comparable claims — it asks to be tried, with a stated criterion for judging the results.
Which is the answer I'd actually give, and it's not really about relevance. Age doesn't make a claim about the mind true or false. The reason to take it seriously is that it describes something I recognise, and hands me a way to check.