I mean it depends on what you consider the "computer", the pile of compute and storage the ship has in that core that got stolen on that one Voyager episode, or the ML model that runs on it to serve as the ship's assistant.

I think it's more believable that the holodeck is ran from separate models that just run inference on the same compute and the ship AI just spins up the containers, it's not literally the ship AI doing that acting itself. Otherwise I have... questions on why starfleet added that functionality beforehand lol.