With Mint (or Mac OS or Windows or Ubuntu), it updates automatically. Or if it doesn't, it flashes an icon, I click the icon, it updates for me.
That's what "it just works" means.
b. macOS doesn't track and update every package on your system.
c. in that sense, nothing just works, i.e. had to repair Windows after a botched MS update quite a few times and while macOS is not usually completely broken after significant updates, (it shouldn't, they control the hw), it tends to be broken in subtle and annoying ways nonetheless, 10.7 for example was particularly bad.
d. That Ubuntu just works is your experience, there are plenty of people who try it and it either cannot detect something, or the GPU driver is broken or Wifi doesn't work, (see the reports on that regarding 16.04 LTS) etc. so it is very subjective, but if you don't experience these issues with Ubuntu, it's great. All I'm saying is that it is the same way for Arch.
That is part of the documentation. Users shouldn't have to subscribe to a news feeds in order to correctly update their systems. Do you subscribe to Microsoft's or Apple's update news feed? If you do, you're unlike 99.999% of users.
"b. macOS doesn't track and update every package on your system."
Mint does. Ubuntu does. A large number of other desktop-oriented distros do, without requiring their users to read news feeds for instructions on manual procedures.
"c. in that sense, nothing just works, i.e. had to repair Windows after a botched MS update quite a few times and while macOS is not usually completely broken after significant updates, (it shouldn't, they control the hw), it tends to be broken in subtle and annoying ways nonetheless, 10.7 for example was particularly bad."
Shit happens. Shit just seems to happen a lot more often on Arch (and Gentoo, for that matter).
"d. That Ubuntu just works is your experience, there are plenty of people who try it and it either cannot detect something, or the GPU driver is broken or Wifi doesn't work, (see the reports on that regarding 16.04 LTS) etc. so it is very subjective, but if you don't experience these issues with Ubuntu, it's great. All I'm saying is that it is the same way for Arch."
I used Arch for ~9 years. I've had systems where it worked fine, and systems that required a lot of fiddling to work.
In contrast, Mint and Ubuntu has worked flawlessly, on those same systems.
Similarly, the config file merging process on Arch is basically 100% manual (I know pacdiff makes it a little easier, but still).
There's more, but I don't think a lot more. Also, if the automatic config in Ubuntu fails you, it's a lot harder to get in and manually override their settings.
It does indeed 'just work', it only doesn't if you fail to understand what rolling release means. There is usually a painless way to upgrade even after a long time, you just have to use pacdiff and read archlinux.org a bit more carefully than if you update daily/weekly.
Also, how does Apple not 'just work'?*
* 'just works' refers to a general idea of it being in good working condition and not behaving unexpectedly, if you use it in a reasonable manner, it doesn't mean that every cranky misconfiguration of a tool you just came up with will somehow read you mind and deduce how you intend it to behave.