It's not that it does, or doesn't exist. It's that the whole common sense notion is literally incoherent.

Religions and denominations of the same religion won't even agree on the nature or existence of free will. Why everyone else is so concerned about the same, I don't understand. It's more philosophy than science in most discussions. If acting as if your actions had internal agency offers better chances of survival, that's a good enough fudge for nature.

There's no way we'll be able to do that until we have an agreed-upon definition of free will. Good luck with that. We can't even come up with rigorous definitions of many common, related words: intelligence, thinking/thought, life. Heck, we can't even define pornography!

All of these ultimately boil down to "I know it when I see it". This sort of definition is not good enough for scientific inquiry. For that reason, scientists tend to avoid such questions.