That’s a matter of opinion.
For cleaning, i don’t unbreech my guns, because it just doesn’t need to be done for cleaning. All that gets dirty is the face of the plug.
I unbreech if there’s an issue, stuck ball, jag, broken rammer, installing vent liner etc.
I do know people that routinely unbreech their guns, and clean them in an ultrasonic and anti size the threads, they certainly know what they’re doing and don’t have any issues with it.
For gun building it’s an essential skill to know, depending on your level of skill sets of course.