This is hard to describe but my fonts in GTK apps now just look worse. Like no anti-aliasing, or not TrueType, or something. Fonts aren't something I pay close attention to, but I noticed that they definitely changed in Waterfox and it looks like they went back in time 10 years or so. They're not smooth and sexy. This happened after a big update where I also got onto KDE Plasma 6.0.3, on Xorg.
I can provide information but I'm not sure what to look for. I'll provide a screenshot but without knowing what it looked like before, it might look normal to you.
I found a few suggestions, like adding this to ~/.xsettingsd:
```
Xft/Hinting 1
Xft/HintStyle “hintfull”
Xft/Antialias 1
Xft/RGBA “rgb”
```
That didn't seem to have any affect after restarting Waterfox.
I think your font rendering looks the same as mine. Do you only notice it in waterfox?
Waterfox is the big gtk app I use I suppose, and it's the only place that it looks weird to me. Another hint, I saw an emoji and it showed up as the unicode character box, which I hadn't seen before. I'm trying to set my system and browser fonts to "Noto Sans" now.
IMO hinting style "hintslight" offers overall better look. Also, autohinting does not always do right things, so that it's better to turn it off, or at least enable "autohint-if-not-hinted" module in fontconfig.
AFAIK, KDE Plasma has its own settings daemon (configured from the GUI), thus xsettingsd would either has no effect, or conflict with the KDE's one.