Could you elaborate? I see no glaring typography problems on KDE (while there are quite a few on macOS, IMO). Iconography – IDK, fairly consistent on the default theme, but it is a bit of a peculiar look.

Aestheticly to each his own. Maybe I'm used to KDE aesthetics. But KDE-on-Linux far outshines the Mac for window management, copy-paste via highlight, Always-on-top, mobile phone integration (KDE connect), keyboard control, accessibility (especially Sticky Keys), keyboard language switching options, click handling in background windows, proper readline support in bash and zsh, integration with third party software such as Emacs (I practically live in Org mode), proper handling of multiple users on a single machine, and so many other things that I just can't think of right now.

Ugly doesn't matter as long as it works better (and I heavily disagree on all of the things you stated.)