There are dozens of OS designs available for Linux. Unlike windows or Mac, you could change most things you think are ugly. There are large parts of windows I think are ugly, for example. Gnome isn’t ugly at all, and actually performs many times better than windows (and sometimes mac). Bad performance is ugly to me.
Linux is beautiful if you have time, energy, and inclination to make it beautiful. Otherwise, like macOS and Windows, it's just some defaults picked by the Adwaita team 2 years ago when the distro cut its stable release.
I used to use Openbox and compile my own freetype with patches but these days want to spend my time on other things, so I'm just using macOS which has the best out of the box experience with the lowest TODO list when setting up a new computer.
There are a huge number of examples here: https://www.reddit.com/r/unixporn/