We are 100%, always bound by past experience and "animal" instinct.
I'm not sure which is more "important", probably past experience in most cases.
Both of these are imbued by a random beginning. To random parents. Who imprint you before you are even conscious, before you have memory.
We are imprinted by genetics (random) and parents/external influences personalities (random).
We become conscious, we already have likes and dislikes imprinted. We did not "choose" these. They just exist within us already, because of external influences (past experience) and genetics (instinct).
We proceed to grow with all these imprints. We feel like we are choosing throughout - but we aren't. We are DEFAULTING. We may be presented with "multiple options", but we cannot possibly choose any of the options but one, because of imprinting from past experience, and instinct. We default to one of the "options". We never had an option. We were bound to do one thing over the others, due to our imprinting from past experience (leading back to a random beginning), and instinct.
That isn't free will. That's deterministic.
Free will is 100%, objectively not possible here. I'm not even sure why it's a debate, honestly, it's obvious it's not possible here.