Why would IpadOS not be held to the same DSA rules as IOS? Apple has applied the same model of gatekeeping (walled garden) to both the iPhone and the iPad. DSA attaches requirements to the gatekeepers if they are big enough.
Software similarity and market positioning don't really come into consideration once the role of gatekeeper has been established.
Software similarity and market positioning don't really come into consideration once the role of gatekeeper has been established.