To simplify a whole lot, there are two schools of thought about why people do what they do. One is that people can’t help it because behavior is an outcome of things that they have no control over, such as culture, childhood trauma, bad influences growing up, poor impulse control due to fetal alcohol syndrome, impaired risk assessment due to an overactive dopamine system, anxious temperament, etc.
The other school of thought says behavior is always “on-purpose”. In other words, behavior is goal-directed - by definition. We therefore choose what we do according to the perceived payoff: what we’re trying to achieve or avoid. The idea of choice doesn’t require a soul, independent self, or homunculus in our heads. It is perfectly compatible with a mechanistic view of neurons doing their thing in a squishy brain. Because the brain is doing the choosing. And thus we have the neuroscience of decision-making.
This really isn’t an either/or contest of ideas. Decision-making requires inputs that are not chosen: what we want, what we’re afraid of, what we think will happen and when, our sense of urgency, our understanding and appreciation of trade-offs, and so on. So the fact that we choose our actions is not to say we have free will. What we have is constrained choice.
But the “choice” part is important. It means that behavior is forward-looking and can be changed with the right incentives and disincentives. Reward a behavior and it will continue. Stop rewarding or even punish the behavior and it will eventually stop.