I'll keep buying Apple hardware (even if the latest rev isn't great) since macOS is the only usable operating system. Windows is (still/increasingly?) a tire fire that's only useful if you're a gamer, and Linux is for programmer-masochists.
I used my first OSX machine ever earlier this year. I wanted to add some extra keyboard commands, so I had to download a 3rd party program that had to unlock accessibility controls and essentially take full control of the machine. That's absurd to me.
I also hit tons of external display problems. Things wouldn't connect or sync right, desktops not correctly moving to the right screens, no window snapping even though it's a high res screen, etc.
I hit way more beach balls/lags than I do with my modern Windows machines.
Windows 7 was solid, Windows 8 was a bit of a mess (as has been every 1st iteration of Windows [98, 2000, ME, XP, Vista, 7, 8, 10]), but Win 10 is really enjoyable.
It's unfortunate that the BSODs caused largely by shitty drivers in Windows 98/XP has hounded the Windows ecosystem for over a decade, even though the driver verifier has fixed the vast majority of those.
I bought a non-apple keyboard and still can't map home+end keys in all applications without a daemon running.
Even after that, things never went smoothly. There was some sort of bug where I couldn't enter my Apple ID security answers in the OS dialog box. Like you, I had problems with external displays, especially with waking up a display when the laptop itself woke up. The very first time I tried to restore from a Time Machine backup I got errors. Problems with iTunes and Photos sync. Not to mention more or less subjective issues I had.
I had more problems with this laptop than I've had with any Windows machine.
Also note that accessibility must be “unlocked” because it fundamentally adds a security risk: processes that can inspect inputs in arbitrary unknown applications have a lot of power. What macOS does is actually a feature and it prevents one of the “tire fires” in Windows.
Beach balls in my experience are usually produced by problems in drivers, or programs that are unnecessarily complex (like the ones that are 400 MB installs with entire virtualization layers instead of being all native code). The OS can only do so much.
External displays: yes, definitely buggy on Macs these days, and with some obscure settings. Something to try: with at least 3 desktops/Spaces defined (need to use "+" in Mission Control), you can right-click on the Dock icon of an application to specify the default space to use for windows in that app. These menu commands are not available with less than 3 Spaces created.
Well, discoverability certainly has been a problem with Apple software lately.
Take Force Touch as an example. Perhaps the menu items will show up with fewer than three Spaces created if you just press it harder?
Because OSX comes with a terminal environment that is almost identical to GNU.
Also haven't had sleep or hibernation issues in years. Though I've used Thinkpads and Dell XPSs which are probably the best supported laptops for Linux.
Despite disliking GNOME 3 when it came out, I got used to it and I honestly think it's the best desktop out there.