Yeah, Stellaris has that too. Ironically, I ended up in a situation where I quit prior to the end of the game during the big endgame crisis. There had been a War in Heaven and both of the two sides were still at it when the big crisis showed up and I was on the far side of the galaxy from the crisis(the invading aliens). Also, the Crisis zone was hitting a group of xenophobic fascists' head on(not that I feel bad for them). So I've got the two awakened empires blocking my path on either side and the fascists' who still want to be at war with me even as invaders sweep through their territory from the far side, so I have to fight my way through those guys before I can even attempt to fight off the invaders, while the invaders take more and more territory and, really, it was just kinda sad and anti-climatic. By the time I could reach the invaders space I was so tired of having to claw my way across system by system I didn't really fucking care anymore and just quit.I often don't finish 4X games, precisely because you inevitably tend to hit a point where it's just a mopping-up operation, and if it's a long and tedious mopping up operation (Stellaris) going through the motions, it's not worth the bother. You've won and you know it, the game just hasn't realised yet.
And got forbid anyone attempt an alliance to fight the extra-galactic threat, even if just a detente. Nope, people were just as interested in continuing to fight me and each other then the invading aliens, because fucking priorities. I mean, I fucking get people are dumb and would rather struggle over petty shit then a common threat sometimes but there's no way to even attempt to convince them "Hey, seriously guys, can we cool it for a bit until the crisis is past? At least let me move my ships through so I can support offensive operations"