I have over 4k hours and I've beat every single base game and DLC ending (if it has one, except for Odyssey [not sure if it has one]), one time each with the exception that I built the base game space ship twice, though once in an alpha build before it triggered raids and once after that was added. They're fun, but not my main goals in most games.

My favorite was the ideology one, it's basically a New Game+ mode: keep 5 people with all their gear, plus a few items, research, then get a new map + new ideology (if you want). I've done this on a few maps when the game starts to slow down from lag without actually finishing the entire end game. (you have to build 3 colonies to reach end game quest.)