FWIW there are a lot of features that are really great on a run, but you might have to switch screens or even manipulate the screen. For instance, zoom in and out on a map. Or instruct your watch to re-route you to the fastest way home, or start guiding you the reverse way you came so you end up doubling your distance when you get back home. You might have other sensors feeding info and the data doesn't all fit on one screen. Maybe you want to control music playback and find playlists subpar (you might want to change based on how you feel in the moment, or pick another podcast because you added time onto your run or the other one ended up being boring, etc.).

Play music and run is fine for lots of people, though, so I'm not surprised it works for you.

Besides the various metrics other have mentioned (and which you could in theory put all in one screen, unless you're interested in a lot of them), you might want to interact with the workout and e.g. set it to the next interval. If you planned a 15min warmup at low pace but already feel good after 10min, you might want to already go to the main part of your workout. On Garmin that's one button away, I'd be annoyed if I had to touch the screen for that.

I'm usually on the same main screen with time/distance/heart rate, but when I change screen that would mostly be for: - Map/routing, useful for trail running or when running in an area you are unfamiliar with - Elevation, vertical speed (useful for trail running too) - Workouts (steps/next step/instructions/duration/etc.)

I may want to pause my run for certain reasons - one time I came across a woman whose dog got off the leash so I helped him corral him before continuing on. There's also times I want to skip a song on my playlist because it's not fitting the current pace/vibe of my run. Always easier to do with physical buttons.