How would watch bands work on a round Apple Watch? Bands can’t have the same attachment mechanism and/or be the same width, they’d have to be much skinnier otherwise half of the space in the watch would be taken up by the bands. Can’t just use pins like any basic watch and require tools to remove, has to be tool free. Could have the bands push in but then it’d be just a pin holding a strap on, not a wedge taking most of the force as we have now.
Apple designed a pretty fantastic mechanism for attaching watch bands, I can’t imagine anything better existing for a round watch, nor can I imagine a round Apple Watch being easily discernible from the bazillion generic Android watches that already exist.
As for a flat edged watch, eww. If I wanted something that looked like a Fitbit I’d get a Fitbit.