I think someone (not me; I do this too much) should file a bug report about this - here. I note that there is a corresponding message when use uses apt (or apt-get) in the terminal, except that, in the terminal, the message is tagged as a warning, whereas here it is tagged as an error - which makes the situation more serious. Source: almost 2 years ago

I don't think the Mint team has said. All that the team has said, to my knowledge, is that some of the 20.2 update will be backported. One thing you could do to try to answer your question is to keep an eye upon the relevant repository. Source: almost 3 years ago

There are a lot of third-party Linux apps built with GTK4/Libadwaita. If you just to to https://flathub.org and click on random apps a lot of them will use GTK. - Source: Hacker News / about 2 months ago

I would recommend taking a look at Flatpak. Source: 6 months ago

Flathub flatpak format apps/games for linux desktop, does not require any specific linux distribution just that flatpak is present on the system. Source: 8 months ago

Which X clients are these? You didn't name any so let's just look at some of the popular and recent flathub apps: https://flathub.org/ I see a lot of games, chat apps, text editors, photo apps, office apps. These all will work fine in XWayland and XQuartz. But also, it's relatively easy to get them running on Wayland natively. - Source: Hacker News / 8 months ago

If you're worried about the potential of breaking things, I'd pick the Fedora Kinoite distro. Up to date gaming support, stable and extremely difficult to break. Install apps from Flathub using the built-in Discover software store and go nuts. Source: 8 months ago