

This is the main argument the GNOME developers use to justify why they don’t support SSD. This is true, xdg-decoration is an “unstable” protocol, and wayland was originally designed with only CSD in mind.
This is the main argument they use but this is not the main reason. The main reason is “design”. SSDs are not a part of GNOME HIG or GNOME’s vision. It’s not that they just ‘don’t like it’. They actively want to kill it, at least in their own ecosystem.
The original 2018 “CSD initiative” blog post has TLDR on top saying, " Let’s get rid of title bars. Join the revolution!" so they consider this a “revolution”.

There is too much focus on GTK4 libadwaita apps in this article. Libadwaita apps already dominate the front pages of Flathub everyday because of obvious bias.
On the Qt/KDE side, Elisa, Fooyin and Cantata are good recommendations.