I don't have Apple Watch, but have Garmin. I used the store once during the initial setup and I don't see why it should be different for AW users.

A lot of Watch apps also get installed through the attached iPhone when you install the associated iPhone app. I think it was the default, I turned it off, to have "Automatic Downloads" on for apps. So if that's still the default (or the present setting for the watch) then if you download Strava for iPhone you'll get Strava on your Apple Watch without ever touching the Watch App Store.

But it's still Watch App Store which installed and delivered the app right? And the developers must use it to give you the application?

Just because you didn't open the UI it doesn't mean the developers weren't forced to go through that app store to reach you.

This is the disingenuous piece if so - as in if the target is non companion iOS, then it’s watchOS App Store? That breaks the logic of the rest of the data disclosure

Most apple watch apps are installed and managed through the watch app on your iPhone not from the app store on the apple watch itself. I just checked and I've never even opened the app store app on my watch but I have configured dozens of 3rd party apps using the Watch app on my iPhone.