You're running VMs on low-RAM phones, what did you expect?
You used to be able to run Unix fine on computers with 64MB of ram. A modern phone has more than enough memory.
Probably more the fact that the memory and battery management logic assumes all user apps which are not in focus can be killed aggressively, which makes the system unsuitable for any background task by design.
Now I am not very knowledge about memory management on Android but I just noticed the 8Gb of the Pixel 8a are almost all used just after reboot. So this is very different than a Linux desktop...
Expecting Android to be just another Linux distro is exactly the root cause of many Termux developers frustations.
> Pixel 8a has 8gb ram. It's not a low end number for Android phones.