There is an end, yes, and it happens a little bit after consuming all of the universe. You'll know that you've reached it when you are offered the option to delete all of your progress and restart.

As with many of the better-designed incremental games, there are moments in UP where you might get the impression that the way to continue is to just do more of what you've been doing, but actually the way to continue is to do something slightly different. I think you're referring to the starkest of those.

Yeah, that's exactly what I was referring to.

It's been a while since I played it, but the key is to allocate as many of your resources as possible to reproduction rather than exploration, because that leads to exponential growth.

It's possible to complete the game in around 2 hours of active play, IIRC.

Well, now I'm stuck in the "combat against drifters" phase and everything is going too slowly, so I think I'll abandon the game once more... :(

The trick is to get the right balance for your von Neumann probes such that they survive long enough to propagate (hazard remediation mostly) while also not bottlenecking on a resource. Iirc you can harvest so much so fast that it's easy to be set for the foreseeable future. I would occasionally just stop mass/wire production to get my fleet going strong and it would take a long time before I needed to restart it. Meanwhile trust stacks up and probes get better.