Apple still has a HIG: https://developer.apple.com/design/human-interface-guideline...
Although personally I find it a bit incoherent (e.g. toolbar versus navigation bar versus tab bar) or (e.g. “buttons” that are just blue text or even grey text in Apple apps).
> Most UX people don't know what that even is.
They shall RTFM then. /s
But the world is evolving and instead of UX people reading the ICCCM they just moved on and created Wayland.
If you have a leak in a pipe just demolish the whole house and build it again.
Most UX people don't know what that even is.