There’s already Trinity.

Don’t know what their stance is on Wayland but it exists.

I still need to make my bingo card.

I’ll take it to use as a computer desk.

KDE themes are scripts. A coding mistake in one resulted in someone’s file system being erased, it would be quite easy to distribute malware via that method.

There are plenty of reasons why themes are bad. They’re a security risk when downloaded from the internet, they’re often not updated alongside the desktop environment causing bugs, and maintaining support for themes is difficult.

But what GNOME does is eliminate choice, not themes.