No, because as of 9.0.0 it was perfectly capable of building ergonomic UIs and works with external tools like Glade. It used to have plenty of features, now it does not.
I haven't tried relm4 because I'm not going to write any apps for GTK4 while it's still broken (egregious text rendering issues, assistive tools like Cambalanche are completely unfinished and unusable in production, inconsistent compositor blocking, etc.)
Plus, relm still doesn't fix the issue of how horrible it is to write GTK code inside a language as restrictive as Rust. With previous versions of gtk-rs you could at least circumvent that by drawing a definitive line between GUI code, builder code, and functional code (what is this, the future?), but now it's all been homogenized into .rs files and endless method calls. What a great development experience! [/s]
> Could you expand on that?
libadwaita has done nothing but further fracture the Linux landscape while pushing the onus onto me, the developer, to re-write the app to look native on other systems. On GTK2 and 3, I could write once, deliver to any platform and have it look as native as any other system utility. It's flexibility is what gave it it's value, since it was mostly just an open-source widget standard that could be used on any system you please. Unfortunately, now that the GNOME team has become the primary development leader of the GTK project, and projects like libadwaita do more harm than good for the desktop userspace as a whole. It provides me basically no value as a developer, and all of the "muh accessibility" and "muh dependability" arguments are total bunk. GTK3 was arguably more accessible since people with vision impairments could activate high-contrast or complimentary stylesheets that enabled them to... actually use the device. Nowadays, my only option is to assimilate into their brown blob UI or get thrown out for being "wrong". Does that seem like Linux to you?