I’d say most Mac users update macOS 
(tho most skip betas).
I usually do an update for point releases and do a complete wipe and reinstall for each major new version or whenever it feels like things are not as snappy as they used to be (using my guide here).
Generally Apple’s update process is pretty good, and you usually do not suffer the kind of slow-down that used to be associated with Windows (not sure if that’s still the case). Although in recent years Macs seem to be going in the same direction as iPhones - where over time they begin to feel slower - at least that’s what I’m finding and my newest Mac is less than a year old! I think I am going to do a wipe and fresh install in the new year.
Be sure to create a Time Machine back-up before doing an update as that way you know you can get back to a working state if you need to. If doing a complete wipe and reinstall do a a TM back up as well as copy your most important files to an external drive - that’s what I do anyway, and there’s more details of that in my guide.
Let us know how you get on Mikhail!