I mean the similarity is not a coincidence. Gaming chairs are modeled after racing seats which are five point harnesses designed to keep the occupant safe in a car crash… exactly like toddler car seats.
I can see a use for actual racing seats in racing games to enhance the immersion. The faux racing gaming chairs took off because some chair company sponsored streamers. Streamers like them because they’re something to look at on stream rather than a bland office chair. For everyone else a bland office chair is way better.
The primary function of the app is to record a GPS activity with your phone. If you already have a GPS watch and like using it, I don’t see the point in using both. And I’m not sure about Coros, but Garmin at least give you the option to manually download your GPS traces directly from the watch without using their web services if you’re concerned about privacy.