I think that both free will and determinism exist.
I think that exercising free will is kind of like swimming against the current while determinism is more like swimming with the current.
Swimming against the current is most likely an illusion. You're always swimming with it regardless of how you perceive it.
Besides, free will itself seems like something that's defined and redefined multiple times to suit one's needs and arguments.
In fact, when you think deeper about it, it's just illogical.
I mean, think of it this way:
If free will is an independently 50/50 probability, then any choice you make is going to be random and not based on any past experience and such. Otherwise, as soon as you invoke past experience, it becomes determinism, not free will.
If free will is not necessarily a 50/50 probability, but can be something like 30/70 in favor of one of the options to choose from, then one would want to know why there's this 70% bias in favor of one of the options. What exactly is the reason that it's not a 50/50 thing? And as soon as you ask for the reason, then you implicitly and inadvertently admit against free will.
See where I'm getting at here?