> Yeah other reasons I've heard of include the obligation to adopt iOS-specific APIs for features like scrolling and text inputs
TBH I'm fine with that. Applications, browsers or not, should use the operating system's components and APIs for things for a unified experience across all apps and interactions. On the desktop side of things, I hate when an application breaks convention for the OS it's deployed on. If I'm using macOS, for example, I want every app on my mac to look and behave like any other, consistent with the rest of the OS.