Read https://ubuntu.com/security/esm carefully. The chance of running everything out of 'main' is close to zero. I am shocked by how little people understand this.
Main is all you need to set up a working system and deploy services. Much like BaseOS in RHEL you get full support for those packages for 5+5 years. With snaps you effectively get rolling releases of LXD, microk8s, openstack, docker and other relevant things. What else do you need? Seriously, how come this isn't enough for a non commercial user?
Because this is Stockholm syndrome, better community options prevail, main is not all people deploy and is not the only repo default enabled. openstack, docker are legacy tech, never encountered anyone using LXD or microk8s thankfully I'll steer clear of that snap garbage barge.