In my world, extensions are required (at the very least, dash-to-dock). But extensions are a second class citizen and often stop working after an apt-get update.
And Gnome forces my machine into heavy swapping. Cinnamon (which is almost the same thing, but usable) doesn't cause swapping.
In any case, in my experience extensions aren't as brittle as you're implying, they generally only stop working after a major gnome version update (e.g. 3.32 > 3.34) which you wouldn't get through an apt-get update.
I haven't had any swapping issues at all, but I suppose this could be hardware dependent (e.g. nvidia drivers are known to cause serious memory leaks with mutter)