EDIT: Almost forgot about Unity, which has arisen from the ashes.
> Gnome / Plasma duopoly
LXQt uses Qt but it's not KDE, Cinnamon, MATE,... use Gtk, but they're not GNOME. And Enlightenment uses EFL, so it isn't part of any Qt/Gtk duopoly.
1. https://www.zdnet.com/article/linus-torvalds-talks-ai-rust-a...
Meanwhile Oxide is building a whole datacenter infrastructure in rust including firelmware, network kernel models and store subsystems, hyperwiser userlabnds in or on Illumos. And say almost universially possitive things.
The people who make cosmic also sell laptops with Rust written firmware. Some of them also develop Redox OS, a Rust OS. They in general love it.
But I guess because mass adoption in Linux hasnt happen it will be impossible to create a new popular UI toolkit.
Gtfo.