It's designed for embedded systems: it's not so much arbitrary GUI applications as a specific one, in fact the OS is more like a library for a single application than a traditional server or desktop OS. It's not that much unlike a single-process docker container, one where it can be quite hard to draw meaningful security boundaries within it. (you can, of course, run stuff as different UIDs, but generally the application needs to have permission to do basically everything on the system, one way or another).
I’ve used it to run autonomous land vehicles. ~60 written binaries and ~20 written libraries, in additional to your bog-standard Linux distro binaries/libraries (core/more utils, ip, user management, etc)
It doesn’t need to be pidgin-holed as a glorified one-app-docker-esque platform. I would argue running a yocto distro as nothing more than a docker host might be the most powerful way to use it even, where the container also runs more than a single “thing” if you will. Just abstracts away the hardware layer from the software layer so as not to muck with the bsp.
