Sure, I agree that 600+ MB of RAM use is not a big problem for most people, but the context here is in the comment I was responding to, which pointed out that i

Sure, I agree that 600+ MB of RAM use is not a big problem for most people, but the context here is in the comment I was responding to, which pointed out that it's not much more than the "lightweight" DEs, so you might as well just use Plasma. My point is that that's a recent-ish change, the lightweight DEs used to use less than 150 MB of RAM, and it's rather surprising how much the gap has closed. I don't know any truly lightweight DEs; to get small you have to use a tiling WM like i3 or sway.