You’re missing the point, nothing is removed from HA Container. Something was added to it to get HAOS/Supervised.
If you were to add the features you think are “missing” to Container, then you’d have Supervised and Container wouldn’t exist.
No, most people invested in Docker installs want to be in control of Docker. They use that install method because they don’t want some other software managing their entire stack.
You’re mis-remembering how you installed HA. Look in Configuration → System → Info to see your installation type. It’s either one of HAOS or Supervised.