> Does Mac hibernate?

Not by default. If you just shut the lid on your macbook and put it in your backpack for 2 days, it does not hibernate.

Which is why waking is instant.

That's what I thought, so I disagree with OP, we don't want hybernation for Linux, we simply need way better power management and hardware that can sustain low power drain for weeks.

Mac M series don't do hibernation, probably because sleep has so little impact on battery life (my MacBook lasts for about a month in sleep mode) and Apple doesn't like to burden users with questions like 'what sleep mode to use'.

That's just plainly not true.

Apple calls it "Safe Sleep" (https://support.apple.com/en-gb/guide/mac-help/mh10328/mac) and you get a progress bar when it wakes from it. Yes, even on magical Ms.

Interesting, never heard of that specific mode before. Does it save the entire RAM or just the OS state and open files?

Most people don't encounter this. It only happens when your macbook battery is about to die while in sleep mode.

Ah yes, I think I've seen this before, it still resumes impressively fast from it, and I think since I normally notice the battery is almost dead it gives itself a good excuse.

It's proper hibernation with all your RAM

Right, that's what Linux laptop needs, not hybernation.