Windows 8 tried to divorce more of the compatibility layers (start them up only as needed) of "The Old Desktop" to a lot of flak from the development community (and some user confusion), but if you were paying attention and used almost exclusively Windows 8 "Store" apps at the time you could get some serious memory usage wins.
Windows 8.1 walked so much of that back and made the Desktop/Explorer and all of its compatibility layers boot first again, but there was a small period where Windows 8 shined.
Presumably this sort of stuff is what the new Windows Xbox efforts are doing again, but the "boots to a full screen experience without 'a Desktop'" expectations of games and game-focused hardware makes it easier to boot the Desktop only if needed in a way that makes sense to game players that didn't make sense to general Windows users with a long tail of ancient applications that they didn't or couldn't "just" upgrade to new ones.