Life would likely be different though; I'd be curious what filled primate's niche before the asteroid.
In one episode, they finally believe themselves to be "home". Until, late in the episode, one of them notices that the Golden Gate Bridge is blue. Supposedly, nothing else is even slightly different than the one they are from.
Well, if we examine that premise, it's pretty dumb. At some point in the 1930s when it was built, someone had to source the paint for the damned thing. The plant that made the paint, even if it was the same one, used different pigments. Mined somewhere other than where they found the raw materials for whatever color of orange the bridge really is. Each of these slight changes, 70 years before the protagonists showed up, would have caused even bigger changes. Trucks taking different routes, causing different traffic patterns, different delays. Suddenly, people are being conceived 5 minutes earlier, or 5 minutes later (or not at all). It's doubtful that anyone born after whenever the divergence occurred (whenever that was) is genetically identical. Doubtful that anyone born even half a generation later has the same birth name.
Pretty safe to say if the dinosaurs weren't godbombed, there wouldn't be humans. The number of magical convergences is too high, even for a shorter period of time.
An alternate idea is that mammals, due to some survivability superiority, were the inevitable outcome and that god-bombing only accelerated us to that. The butterfly effect is sci-fi.
If you want wild speculation, imagine there was no accelerant and lizard-people eventually ruled the planet — perhaps in the way we're headed, they would end up god-bombing themselves ... and then finally the mammals get their (long over) due.
Popular opinion seems to be that the cockroaches are waiting their turn.
But just because some mammal or another evolves into a sapient doesn't make that sapient "human" in the way we're using the word in this context.
The path from the little critters that existed at the time of the dinosaurs to H. sapiens today is very specific, and we know of at least 2 or 3 bottleneck events in our recent evolutionary history. The idea that our species could have arisen anyway is beyond absurd. The universe does not work in this fashion.
Guess that's where I disagree with you.
Such that, at the end of it all, we have something that either or both looks like an anatomically modern human and would (hypothetically) be able to have fertile offspring with a H. sapiens human?
Because, I have to tell you, that's pretty batshit.
With rain forests, something would have filled the primate niche. That something might well have become human-like.
While humans faced genetic bottlenecks, I'm not sure that affected all primates the same.
After the KT event that killed the dinosaurs, mammals sought to fill the niches left by dinosaurs. They grew big and huge. The few dinos that did survive, sat at the top of the food chain, enormous flightless birds. Sharks took over in the water because all the reptiles that were there were gone. It took mammals 40 million years after the bomb dropped to slowly spread over and gently outcompete the big bads. Collectively.
But it couldn't have happened in the first place without Giant Meteor making the choice for us. The Cretaceous was just that gnarly, and it would have only gotten gnarlier. The world found a local maximum, and then that maximum got flattened. The only thing that could have ended it, did.