I think Nintendo is the only company that could compete and introduce its own app store/walled garden. Chinese companies, even Samsung, cannot have their own walled garden because nobody wants to specialize for them, as they offer no unique benefits.

I assume it would succeed with the general public due to AAA Nintendo games being supported, but I also think Nintendo would have the opportunity to introduce a blue sea for Japanese business software to be introduced.

I also think that SteamDeck, with its desktop support, shows the interest in something that can replace desktop/laptops[0]. Also, I think this could compete in the desktop area like Microsoft Continuum[1].

It also introduces a new vector, that is non-American, for surveillance, except in this case it would be via Japan.

[0]: https://beebom.com/how-use-desktop-mode-steam-deck/

[1]: https://www.microsoft.com/en-us/windows/continuum