Comment by black3r

The market's only thought about the OS is what features it supports. And lots of them are provided by 3rd party apps. Lots of people switch from Android to iPhone and back. People mostly just want to keep using their TikTok, Instagram, WhatsApp, ...

It's the app developers (and their companies) who wouldn't be happy with a third option, because the existing two cause enough problems, just think about how many frameworks for cross-platform app development exist, they were created for a reason..., and even with them you still have to do OS-specific stuff to tackle different app store policies, different privacy features, updated APIs breaking your app on new OS versions... or you can have two entirely separate teams working on two separate codebases and try to keep the feature parity...