> its functionally a point where Ubuntu could un-seat macOS in terms of ease of use
And this is in turn is seriously un-true.
* With my Macbook, I can be almost ironclad certain that if I close the lid to sleep, it will wake up. With Ubuntu (or any Linux really) you have 99,5% certainty, which is great, until it isn't and you lose work.
* Battery life if still miles behind macOS+Macbook levels unless you compromise somewhere (resolution, portability, etc.)
* Apple is quite a heavy-handed overlord that pushes changes through, and developers have to adapt or die to them. Ubuntu has no such power.
* Most macOS developers also 'naturally' stick to platform conventions, so all applications feel at home and look and work as expected
* The ease-of-use of Apple's 'global menu' cannot be overstated. It may not matter much to techies, but for my mother or grandma the fact that 'Print' is always under 'File' and 'File' is in the menu bar regardless of which application is being used is magic. Same goes for 'Edit', 'View', etc. They never have to hunt for these things again[1]
That's not to mention Touchpad gestures, Spaces (best implementation of virtual desktops), scaling, font rendering, updates that rarely if ever bork everything, ecosystem integration with your phone and tablet (Continuity, shared copy-paste and remotely-triggered tethering are a godsend), etc. etc.
Now if you were touting that Linux is much easier to tweak exactly to your liking, I'd heartily agree. But even today, I'd much rather recommend someone a Macbook than have them deal with the headache that Linux desktop _can_ be.
[1] Yes I know Ubuntu had a global menu. They nixed it, and the Gnome extension is a hack that doesn't work for everything