Obvious to me, irrelevant to the groups targeted by these wars. In the WW2-era, the stakes were literal annihilation: a number of minority groups were specific

Obvious to me, irrelevant to the groups targeted by these wars. In the WW2-era, the stakes were literal annihilation: a number of minority groups were specifically targeted for extermination by the belligerent powers, and many others were occupied under threat of extermination. Today, the stakes are that you face random drone strikes and your weddings get blown up. But there's nothing you can do about this: instead of "if you accept our rule, we'll let you live", it's "we're not interested in ruling you, die anyway". When wars are fought to make a point rather than to win, and that point has nothing to do with you, they're not going to change your behavior. So great powers and separatist/extremist groups exist in symbiosis, with each constructing and reinforcing the other in the absence of an external reason for their existence.