I've used MacOS for about 15 years now, and I almost _never_ use full-screen [1]. What I do instead is group windows in the different desktops by task / context. These windows are mostly sized to take ~80-90% of the screen, but I make them all different sizes and slightly offset from each other. That way I can switch from one another by clicking on the small sliver that peeks out from behind the current foreground window. That type of context-switching is a bit more rare; the most-used action is the 3-finger swipe / ctrl-arrow.

One thing I miss from Leopard is the ability to put your spaces into a grid instead of a line; made for a bit more efficient switching between them.

[1]: The only exception which is pretty much always full-screen is my terminal. I use tmux for multitasking in that "space".