Sharing my experience:
One of my wheels had air problem: Tire guy could not figure out what was the reason. I keep driving getting air every week, for a year. I changed it last week. The mechanic showed me inside the old tire, it had good amount of rubber scrubbed from the inner tire.
If we drive vehicle with low air pressure, the inner tire wall starts thinning gradually. : It is not okay to drive vehicle with low air pressure for a long time. I was suggested not to drive flat tire to nearest gas station/ rather use extra tire.