I think that in isolation this would be true but I don't think it would be true in reality.
Lets use one of the big drivers behind this debate as an example: Epic
Epic want this to happen so they can release their own competing App Store, they've quite literally admitted to this in court.
Another industry Epic is trying to make moves in is the PC game distribution market with their Epic Games Store and their actions over the last several years honestly worries me if it were to be translated to the mobile app space.
'Don't be afraid, you don't have to use their store' you'd say and if a competing store was the only effect this had then that would be completely true but that's not true in reality.
They've thrown millions at developers to release games solely through their Epic Games Store, games that were initially to be released through competing platforms like Steam and GOG that people actually *choose* to use.
There's a laundry list of games that you can now only get through the Epic Games Store, this isn't because they are made by Epic or their Games Store is the go-to platform for people, it's because they've paid developers for exclusivity to the detriment of users who now have zero choice to go elsewhere and use a preferred platform.
The choice isn't Steam vs GOG vs Epic, there is no choice, it's either use the Epic Games Store or you don't get to play the game.
I don't want a world where the Epics of the world start throwing money at app developers for exclusivity and turn app distribution into the same fractured and disjointed mess over several different app stores that end up giving consumers zero actual choice and only serves to force them into using platforms they otherwise wouldn't choose to use were it not for this type of behaviour.