It’s also not scalable if every app starts running background processes on an operating system without “virtual memory” - yes, I know there is a difference between virtual memory and swapping to the disk.
Even stock android does not guarantee that background services can run indefinitely, but Google at least provides clear rules what process may run how long in the background and under which circumstances it is killed. I have no idea why the manufacturers are allowed to blatantly break those rules and still brand their operating system Android.