There's almost no reason to do anything weird with operating systems today, because you can run Linux on a single core of your multi-core machine, and your app

There's almost no reason to do anything weird with operating systems today, because you can run Linux on a single core of your multi-core machine, and your app at full throttle (no context switching) on the remaining cores. So for the cost of <1 core and a small amount of RAM>, you get full Linux, full debuggability, SSH, file systems, networking, etc. and your app still runs as fast as it can on the CPU. Spend your innovation budget on your app, not the OS.