I had the same reaction to light themes but had to use a light theme because on dark themes I found the text hard to read. Then I lowered my screen brightness and no more burning eyes with light themes lol.
I just love 90% of the defaults for Linux mint. People crap on it for not being Wayland or cutting edge in every regard, but it just puts so much old school polish on it.
I was super into the Wayland hype train when it was new -- back in the "wobbly windows" days to show my age a bit haha -- but at this point I don't actually see much benefit from an end user perspective. I am also a former XFCE user, so yeah...
I get the arguments, but if the community or Linux wants to get larger market share everything should be done that is possible to make it so people never need to know about X11 or Wayland. Depends on the goals of the community of course.
I liken it to cars. I don't want to know the difference between a flat 4 and a V6 or an AWD and a 4 wheel. I want a car that gets me places without spying on me and being an unmaintainable pain. You are either a car person who wants to know a lot and do things yourself, or you just want something that works and you don't need to know a lot about. I myself straddling both worlds in Linux depending on the day.
The one thing I don’t like about Cinnamon is that it doesn’t play nicely with flatpak theming at all. KDE seems to apply themes over flatpaks with no problem no matter the distribution. If the Mint team built into Cinnamon desktop these theming capabilities, I’d use it over KDE all the time happily.