I mean, at least Cyber Sleuth has a real online match-up system.
The thing is that the primary focus of Digimon isn't really about competition this days and they focus more on story and development.
A franchise that its primary focus would be the competitive side of things would be Pokémon, which only lives to this day because Game Freak only tries improving and polishing the competitive side of the things more than, well, the game itself.