Really only SSH and sudo broke. sudo would still work but you'd have to re-enter your password every time. It was a painful experience and I'm glad I know better now.
As a one time noob I may have done this once or more.
To get one thing working I borked everything.
Understanding permissions is pretty basic. But understanding permission requirements for system and user apps and their config and dirs can be a bit overwhelming at first.
Thinking a little change to make your life simpler will break something else doesn't always register immediately.
Shit, even recently, wondering why my SSH keys were being refused and realising that somehow i set my private keys world readable.
Nah, there's something broken, I think it's because group render under the container has a different GID than the container so the acl fails and you either sudo or chmod.
I use podman and since it runs as my user it has exactly same same permissions as me. I just add my user to the proper group and it works.
Anyway for LXC you could just passthough a folder and then create a file. From there you can look at the file on the host to see who owns it. That will give you the needed information to set permissions correctly
Ahh, I'm running priveleged containers, I wrote my own scripted framework for containers around lxc in mostly python.
Basically I fell head over heels in love with freebsd jails and wanted them on Linux, then started running x11 apps in them, it's my heroin.
Haven't used podman outside proper k8s for work, did proxmox for a bit, but it was just a webgui for the same thing.
There were a bunch of online bug reports about the /dev/dri issue, maybe there's a better solution now, but since this is my workstation I wasn't as worried about security.