Many DE have received substantial improvements over the last couple of years. It sounds like you're really looking for something lightweight, more than you are something that is fully featured. I don't have much experience with the lightweight Linux DE, because when I need performance I just use command line like you do. I'm sure if you did some searching, you could find a really snappy DE, but it doesn't sound very important for your use case. Definitely do check out some of the full-featured desktops though if you ever decide to use Linux as a primary PC. Several of them are really slick now.

It's really not a problem anymore. Look at a distro like Mint, compare the lightweight xfce version versus the full fat Gnome cinnamon. They both look the same on the surface using the same theme, all apps work, look and behave fine over all versions, yet you've got the option between "small and snappy" or "pretty and high end" which works much better than turning off the animations in Windows.

I've been an on/off Linux desktop user for years and now is just a comfy time to be a Linux user. All websites work, most of my Steam/Epic and GOG library just works with no messing, the various software stacks we use day to day are there, mature and "just work".