If we can't get it right this time, there's no indication a reboot would be any better (because humans).

I don't know. I mean, things could have gone very differently (in a better or worse way) and the world may be unrecognizable today if certain key events did not happen.

Like if nothing sparked the World Wars (conversely: or if Hitler won). Or Greece harnessed steam or electricity to spur an industrial revolution 2200 years ago. Or if Christianity etc. never caught on.

who says the next time will be humans? there was no next time for the dinosaurs. maybe humans are not the end, but just a rung on the ladder.

How about squirrels? I think it would be fun to have a tail.