Well, you could also decide to pay a linux distribution of your choice.

KDE is a German project, GNOME a French/German project, most of Debian's maintainers come from the EU, Manjaro is a German project, probably most Arch, NixOS and Alpine maintainers come from the EU as well...

The problem with open source projects is always "unopinionatism". The only project that comes to mind where the design language feels actually integrated are KDE Plasma (not before) and maybe elementaryOS.

But those projects need a lot of funding to come to feature parity with Microsoft's and Apple's alternatives. Especially in the enterprise/corporate product portfolio, and system landscape administration.