This is actually happening in China to some extent.
I'm blown away that Apple and Google actually approves apps that run a mini-OS inside them like WeChat/Alipay. I initially thought they would have rules to kick these apps off their store. These mega-apps are able to run mini-apps that effectively bypass any control from Apple/Google, the loss of control on their end is maddening.
Google and Apple have no control over whether WeChat mini-apps respect their respective App Store rules and guidelines for example. Also, WeChat got so big that I wonder if they would even ban it from the app store if transgressions are found. WeChat literally took control away from them.
Example : people install WeChat, from there install mini-apps that aren't controlled by Google/Apple, and even can pay though third party apps : Google/Apple don't get a piece of the cake like they would if you used their IAP system.