[hotdog97]

Addendum:

Platforms are because of the market dynamics remarkably long-lived. In the case of iOS, the APIs date back to like 1985, with Next Inc. In the case of Android, back to 2003.

The platform-level APIs and frameworks tend to be grown organically, in a way that is quite far away from the yearly fads.

It's really hard to hire people who are actually good at the core aspects of these platforms - most new devs seem to get sidetracked by the latest shiny framework, that will then die 3-5 years later. Meanwhile the platform APIs live for multiple decades, and take a lot of effort to master.