Everyone needs to characterize (not “calibrate”; that term is highly misleading) their display. The question is just whether you keep the characterization provided by the manufacturer, or measure the display yourself using a hardware device. Either way, the result is a display “profile”, which is basically a lookup table used by software to map color coordinates so that they will appear as expected on the display.
People using Macs certainly do care about ColorSync. That’s the name of the software which uses the display characterization to keep colors looking as expected throughout the operating system and most applications.
In many professional environments the preferred route is to use specialist hardware to send an RGB signal at a high bit rate and do any colour transformation in the monitor hardware.
Using LUTs either at the application or OS level to adjust colour information is a big no-no, although that doesn't stop some people from doing it. You simply don't want to change your colour space[1] until you absolutely have to.
The point of calibrating your monitor (which is a hardware + firmware level problem) is to see how your RGB image will look on a colour space restricted piece of hardware (for example in video this is often 12-bit RGB --> Rec709).
If you have some image data stored with reference to one color space, and you want to convert the data to a different color space (e.g. because you are targeting some particular output device), that is a gamut mapping problem. To learn about different trade-offs involved in choice of gamut mapping algorithms, I recommend Ján Morovič’s monograph, https://www.wiley.com/en-us/Color+Gamut+Mapping-p-9780470030...
Same story if you want to show your image on a display with a different gamut.
Most gamut mapping algorithms used in practice (whether on a display or in software) are actually pretty mediocre in my opinion. It would be possible to do substantially better by writing your own code, at the expense of being a bunch of work. Alas.
P.S. The Wikipedia article about color space (and articles about many other color-related topics) is pretty terrible, but I’ve been too lazy to rewrite it.
If you need color accuracy then you're calibrating your monitor hardware.