I’ve thought about trying a tiling window manager, but I don’t think I’d get the benefit. I don’t really do a lot these days and normally just have one or two things going concurrently and with two screens that’s trivial to layout.
The main thing I struggle with (with my old eyes) is things like Firefox that override the normal window manager decorations - I find the edges get lost and they blend into each other. A tiling window manager would help with this, but I just turned off Firefox’s ability to do that.
I’m not sure how long ago “not that long ago” is for you - I just had a look through the history of KDE and, based on my familiarity with the various screen images posted there, I think is about 20 years since I last tried it :-)
I’ll have a look at cinnamon and cosmic - thanks.