alt Hacker Newsgtk1/gtk2/gtk3 code will require you shipping gtk(version) on modern linux, not all distros have the legacy libraries.
Apple deprecated carbon (which was a thing when gtk1 was around). I don't think you have an option for this on their ARM hardware.
QT1->N code has the same problem, the older libraries are not shipped on most modern linux.
I do absolutely understand if you're going to do static compiles, that can work around that problem, but that arguement nullifies everything, since you can run/write/execute anything in a turing complete system, if you complain you're just not dedicated enough.
Carbon was released in 2000 and final release was in 2019. Cocoa, correct me if I'm wrong, was released in 2005. That's 14 years to learn it. Not like you knew Carbon when Cocoa came out because there were like 10 developers making Mac OS X apps before 2007.
y'all are slow learners if that's an issue for you, but React doing major breaking changes at least once a year is totally fine.