In general I disagree with what you're saying, there are still tons of programs that don't have any cloud syncing, plus not everyone wants to use that. There's also many WM/DEs that do not re-open running programs or keep window positions, including basically all the ones I use. Plus I also run many programs as different users, for privacy/isolation purposes, which no DE can handle in that case.

I also have historically (and still) had major issues with suspend/resume when a discrete GPU is involved or some other hardware device that linux can't resume properly, I always end up having to just reboot anyways which defeats the purpose.