I think if it is your first watch, you don’t even think about some functionality that is not there. If you already had a Watch before, you expect all the newer ones to include functionality that you are used to. And this is what people see as essential functionality. And other do not miss it.
Just as an example the other way around: If you have a Suunto, you are used to see running timers in the watch face, you are used to the auto sorting of sports mode for last recently used. Garmin - as the usual example - has neither of them. Sure, you can dedicate one data field to a running timer, but Suunto solves this way more elegant.
It’s just expectations…