I think that basic KDE looks pretty ugly. I used vanilla gnome for 6 months and loved it. I know about the subreddit unixporn and some “well themed” KDE DE look really good. I wanted to know that if it’s worth it to customize your Steam Deck DE or should you just pretend that it’s just functional and you shouldn’t touch it. I mean the Steam Deck uses an APU…would it drain a lot of memory to display something more “elaborate”?
Changing the KDE theme shouldn’t significantly impact resource usage…
That said, I don’t mind the vanilla Breeze theme, though I do set up a custom color palette in the settings that goes darker than the default dark theme, and enables wallpaper based accents in more places. You can get pretty far with just the colour editor.
Then there are themes, and kvantum, but they need to be maintained lest they break with updates. Most themes do not live long, and while I forked and edited one myself once, it wasn’t worth the effort for me to keep fixing it every update.