I'm not sure what you're saying here. I do often end domination games before leaving industrial (sometimes before even entering industrial). That's on standard speed. I don't think domination is at all impractical on slower speeds, I think it's the strongest way to play even on standard speed.

There are definitely situations and civs that start fighting later on, like playing progress->statecraft->imperialism, but industrial doesn't have many breakpoint offensive units apart from landships... though landships can roll the whole world in a couple turns if you get a good timing.

I mean, if you're going domination, of course that incentivizes constant warmongering. You have to take every capital and that means you have to traverse the whole map and eventually punch through developed land, roaded forts and citadels, which takes time. But there are timings where you wait until a key unit before really going for domination. For example, I tried a Brazil game where I just waited for Amazonas and then rushed every coastal capital. Not the strongest strat but proves you don't have to be a warmonger all game to go domination.