Well yes, you basically come to what i've been writing about so far: the issue is with libraries like GTK 4 that break ABI backwards compatibility. It isn't the issue with Linux, Linux doesn't break ABI backwards compatibility - if GTK 4 didn't break their ABI you could use the GTK 3 API as a baseline for your application and dynamically load the new GTK 4 stuff (and as a bonus you'd get any inherent improvements that might be there in GTK 4 that are exposed through the GTK 3 API, like how -e.g.- applications written for WinXP get the emoji input popup on Win 10 even though that didn't exist during WinXP's time).
The REAL problem is libraries breaking their ABIs, not Linux itself.