Well might also depend on the time you started playing.
I played through XCOM2 twice when it was new (and used some changes in .ini files to lower the Graphics further) it was really playable - though I would need to reload in the final mission once or twice and in “base” defence mission to avoid some memory overflow (probably because of the shared use of the RAM by CPU and onboard GPU). This overflow would start to change colours in a strange way and really crash windows 10 if the game was not stopped or reloaded in time. It were the only 2 times I really saw my win10 crash like in Win95 times.
Later there were big updates for the game which made it even bigger in size… Tried to play for a third time but faulty Graphics started coming in normal missions. I decided to stop playing then.