On machines where you start Steam manually in order to play a game, do you keep Steam running in the background after play session is over? Meaning if you no longer play any game for the moment, and just keep it running to be ready. Or do you close Steam, after the play session?
Steam has a whole browser in it, active DRM, updaters and tons of other features sitting and polling in the background. Measuring it, I found it to be heavier than a browser (though admittedly not one with a ton of tabs open).
On Linux, I also noticed it takes a good chunk of VRAM.