GNU/Linux doesn't have desktop stack capable of matching Objective-C, Swift frameworks both in feature set and related GUI tooling.
Do I like it when things are pretty? Sure.
Do I need them to be pretty to get shit done? No
I know that is what drove me away.
Most just want a window manager for xterms.
Designers get bashed because they don't know what people want.
Performance on GUIs gets bashed, because what matters is doing xterms over remote X connections.
Glances at 2nd and 3rd monitors
Well I can't argue there.
Not much in that department, either. Nothing that beats the proprietary software staples, especially for creatives, that I happen to use: no Cubase, Pro Tools, Photoshop, Premiere, etc. Lots of apps ranging from "close but no cigar" to "why even try?".
https://developer.apple.com/reference/
Not to mention the related GUI tooling.
Where is Instruments on QtCreator, for example.
The GNOME project itself [1] has a lot of projects which compete with what you linked. Sure, Apple has a few billion dollars to dump into development every year, so you have to adjust for scale.
Qt alone exceeds the feature set, has more GUI tooling, and is multi-platform. That's just Qt, and the same could be said for GTK. I'm not slinging mud at Obj-c and the frameworks Apple maintains, but they are not unique snowflakes without equal.
https://developer.apple.com/reference/
I can find tons of entries without parity in Qt.
And their current trend to invent a different flavor of JavaScript every few releases, no thanks.
GTK+ is no competition for these APIs:
Still use GNU/Linux on my travel netbook and of course, some of our servers run it. Last time I used Qt in anger was 5.3, while trying to do a mobile project that I eventually ported to pure native APIs.
Do you know of any other frameworks, besides those that cover all of these ones?
