Thanks for the reply,
Specifically it is the central place I go to in order to see trends relating to improvement of my HR when doing any activity.
Zwift -> (future) writes heart rate
My bluetooth enabled stair climber has an app that -> writes heart rate
As my fitness improves, I am able to see in one place the better/lower HR for known circuits/segments/workouts/etc as I progress through these activities regularly. (I am actually also waiting for Strava to write HR as well, so that when I do outdoor rides the above will be true no matter if I use my stair machine, ride Zwift, or ride outside)