I can't make the concept of free will hold still. Start with a simple observation: there's no evidence that anything happens outside of nature. Real agency — a genuine choice — would require an effect with no physical cause, and if that happened consistently you'd be able to see it: an event that reliably occurs with nothing physical behind it. People sometimes point to quantum mechanics as the loophole, but it's statistically consistent, and whatever wiggle it allows is random — and randomness is not freedom. A coin that flips itself isn't making decisions.
Even if you grant some metaphysical spark, it's swamped. Your memories are stored physically, those memories build the models your conscious mind runs on, and those models drive your choices. The physical world has its thumb so heavily on the scale that blaming — or crediting — some free-floating soul for your actions seems unfair. The line I keep returning to is "free will is the ability to gladly do what I must."
So where does the feeling of free will come from? My guess is that it's social. The real world is infinite shades of gray, and tracing why a person became, say, a murderer would mean following the causal chain back to the beginning of time — which is impossible, and which, taken seriously, lands the blame on whatever started the chain. That's unbearable to run on. It's enormously easier to draw a line, call one side right and the other wrong, and act accordingly. Our whole society is built on that simplification: it lets us handle broken, dangerous people by labeling them evil and setting them apart — not because the label is metaphysically true, but because we couldn't function without it.