Comment by pjmlp
Currently Android is the best we have gotten thus far in that sense.
- Managed userspace
- OS services can be written in Java/Kotlin if desired, and some actually are.
- NDK has a limited set of use cases, mainly for writing native method implementations, 3D rendering and real time audio, and POSIX isn't officially supported beyond to what ISO C and ISO C++ require for their standard libraries implementation.
Naturally OEMs and people that root their devices, push stuff directly with ADB to their phones in developer mode have a different view, but I am writing from the point of view of how the OS behaves in normal devices, by people that don't even know there is such thing as the magic incantation to enable developer mode.
Is this the best we can have, I surely hope not.
I also would like to see something similar, but industry always takes one step forward, two back, in this kind of stuff.
By the way, look into TamaGo, Go based toolchain for bare metal programming firmware.