And sure, you can have some empathy even if you don't have all of the empathy. But those are definitely not orthogonal concerns. Being able to empathize fully with someone's situation IMO includes recognizing that everything truly is luck. Like down to your genetic makeup. Hell, being alive is lucky.

That seems like a content-free and useless definition of "luck" to me. What value do we gain from pointing out that "being alive is lucky"? We're deep into "shit nobody can do anything about" territory here.

Again, I don't dispute that different people start from different positions in life, but my position is that we should focus on doing things to broadly expose opportunities for everyone, and then providing support for the the truly unfortunate who are not able to take advantage of any opportunity. But I have NO problem with unequal returns in terms of relative achievement between people who start in similar positions. Some people simply do work harder, and create more value. I don't see any reason they shouldn't benefit from that.

what's the point if they're not seeing equal returns?

I don't see why anybody should expect equal returns, especially not in terms of lockstep "moment in time for moment in time" comparison. Success won't come at the same time for everybody. We should also keep in mind that "success" is not a binary operator... it's more of a continuum - not to mention somewhat personal and subjective anyway.