My favourite example is one that the OP mentioned - not supporting multiple stream transport on Displayport. For those who aren't familiar, Displayport MST is a feature that allows multiple streams over one Displayport cable. Some monitors support this directly, meaning you can have
Macbook -> Display1 -> Display2
Macbook -> Display1
Macbook -> Display2
Except they don't support it for this.
What they support MST for is to allow vastly-higher-resolution displays on macOS, such as 5K displays, by splitting the display image over multiple stream transports to bypass the limit on resolutions and refresh rates that Displayport provides (or provided at the time).
For some reason, they just haven't bothered to implement MST to allow for multiple displays; it exists and is supported, but only for high-resolution displays. This is great if you're googling around and see that macOS supports MST, then you buy monitors which support MST and hey surprise it doesn't work and there's literally no indication why.
Dell makes some Displayport monitors which support daisy chaining.
Linux, however, is another story. Bad sleep support, forget about printing, scanning, GPGPU computing, etc. We use it when we have to.
I upgraded from thinkpad x240 on which sleep worked perfectly too.
Based on...? Apple is pretty straightforward: they support hardware until they don't. And they're quite explicit about ending support and it's almost always a major release. You might be able to hack support after that, but I've literally never had it be a "toss-up" about when Apple was or wasn't supporting their own hardware.
As for Windows... I've got a 10 year old 2600k based desktop that runs the latest version of windows flawlessly. I guess if you go back 20? 30? 40? years you might find something that can't run the latest version of windows, but you're going to be down a really, REALLY obscure rabbit hole. I can't say I ever recall it being a coin toss, it was about 10 seconds on google of finding or not finding a driver.
Linux on the other hand... the support of hardware is awesome, but determining if something is or isn't supported is generally an afternoon of reading mailing lists.