Suppose the sceptics are right and nobody is ever the ultimate source of what they do. The interesting question is not whether we would still hold people responsible, since we plainly would, but whether we should, and in what sense.
Two kinds of responsibility
The distinction that does most of the work is between backward-looking and forward-looking justification.
Desert looks backward. On this view a wrongdoer should suffer because of what they did, full stop, quite apart from any good the suffering produces. This is the notion that the free will sceptic attacks most directly: if the act traces to causes the person never chose, it is hard to see how they have earned anything.
Consequentialist responsibility looks forward. Praise, blame, and punishment are tools that shape future behaviour, protect people, and sustain norms. None of that requires ultimate origination. It requires only that people respond to incentives and reasons, which they demonstrably do.
What a sceptic would change
Derk Pereboom argues that abandoning desert would improve rather than destroy our practices. The medical model of quarantine gives him an analogy: we may confine someone carrying a dangerous infection without supposing they deserve it, justified by the protection of others and constrained by the least restrictive measure that works.
Applied to justice this yields incapacitation where genuinely necessary, heavy investment in rehabilitation and prevention, and the removal of retributive suffering as a goal in itself. Sceptics point out that a system built on desert has produced practices that are hard to defend on any other ground, and that the countries treating punishment as regrettable necessity rather than moral payment tend to reoffend less.
What we cannot give up
Peter Strawson argued that this whole way of framing things gets the order backwards. Our practice of holding people responsible is not a theory we adopted on evidence and might abandon on evidence. It is built into the reactive attitudes: gratitude, resentment, indignation, love, hurt feelings.
You cannot resent a hailstorm. You can resent a friend's betrayal, and that reaction is not a conclusion from a metaphysical premise about origination; it is part of what it is to be in a relationship with someone. Strawson's claim is that no general thesis about causation could dislodge these attitudes, because giving them up would mean giving up personal relationships altogether, adopting toward everyone the detached stance we reserve for the very young and the seriously ill.
Where this leaves us
Most contemporary philosophers land somewhere in this neighbourhood. Whatever the metaphysics, the distinction between the coerced and the willing, the deluded and the clear-headed, the person who can be reached by reasons and the person who cannot, is real, and it is the distinction our practices were tracking all along.
What the debate does deliver is a steady pressure toward humility. Nobody chose their genes, their childhood, or the moment that formed their temper. That thought is compatible with holding people to account, and it is a good reason to do so with more mercy than comes naturally.