Hard determinism makes asking "why" meaningless.
A lot of people say "What was the point in evolution/our brain/x if there was only one outcome/(its purpose)?" , and here is my answer:
Just because.
The reality is that anything that happens was meant to happen (assuming quantum events rarely cause macroscopic ones) . Hence, asking "why" to a given circumstance doesn't make sense, it just had to be that way. Evolution does not have a "point" the same way the fact that specific leaf on the road blowing by does, everything you see is governed by the same physical laws.
"So why do I ask why?"
Just because. Your ability to say why was written into T+1 seconds after the Big Bang, there is no "point", nor lenience it what "could have happened" during then and now, with the intermediary of evolution.
Your brain doesn't "simulate outcomes" in a meaningful way that implies it could actually "have done otherwise" given the same circumstances, it does it just because it had to given history.
"But it's counter intuitive, and that tells us something, right?"
What makes you think that your counter intuition is not also part of this loop? That philosophical rebuttals are exempt from physical laws? Even this reddit post was written into time 50 years ago. Possibilities are illusions caused by a lack of data, and "as it happens" we aren't omniscient.
The conclusion? That the more important question is:
"Why was the matter in the Big Bang/dawn of time composed and arranged and exploded in such a manner, be it intrinsically random, by some being, or beyond epistemic reach, to entail "why", to entail "you", to entail ANY specific event, & absurd "intuitively" meaningless things like the invention of vanilla ice cream"?
Is there inherent meaning in physical events specifically because they were "made" to happen?
The answer will never be found out and that is the real existential suffering of rejecting free will and being convinced by hard determinism.
My personal view: Simulation theory is becoming more attractive/multiverse .