I've not knowingly had a gun with a bad compression tube, evert. Pretty sure I'll have had one or two, though, but been blissfully unaware. I suppose that unless a gun fails to deliver the expected power output or the force when re-inserting the piston is inconsistent, many "average" users won't be aware.

At least it'll be an easier fix on guns with sliding comp tubes.

The worst I've seen on one of mine is the Mercury S I tinkered in the Winter, where the model designation stampings are visible on the inside of the cylinder. Not too sure if this has affected anything.....piston polished, a smear of high moly content paste on the tail and some moly grease on the inside of the cylinder behind the piston when at the forward position and all seems smooth and fine.

Problems in the compression area itself will present much more of an issue, as you indicate.