Consider your assertions contrapositive.

If hard work implies good outcomes. --contrapositive -> If bad outcomes implied bad work.

I don't think it takes a lot of life experience to see that the above is not true. I argee that hardwork can definitely be corrolated or rather feels corrolated in retrospect but its not a given. Some of the hardest working people are paid the least if you adjust for the hours they actually work, or if the inherent value of their work is low (you mentioned failure to generalize) but even in specific case of tech its not a given that hardwork will actually make the differnece.

Almost no amount of hardwork can overcome the better sitution some people are born into / inherent. Someone staving in africa just isn't going to be the next physics star or atleast the statisistics don't predict them. There is certainly an equalization curve where if you incoming connects and circumstances are good enough hardwork because the decider. But your starting conditions play a huge role on where you will land in the grand scheme of things. You certainly can change your outcome but sometimes hardwork is not the same as smart work, if getting a promotion is 5 year process at your current job or moving to a new place. The better outcome actually comes from working less. I think some other commenters mention this as well.

I don’t know too many unsuccessful people, to be honest, so it’s hard for me to evaluate the contrapositive. The few unsuccessful people I do know definitely show a pattern of not working as hard as the typical successful person I know.

I definitely agree that where you start has a huge impact on what’s possible. I am not saying that a really hard working villager in sub Saharan Africa is going to get better outcomes than the lazy child of an upper middle class family in the US.