That might be a standard dimension, but what I meant is that not all so-called 22" bags are really 22" the way the airline measures it (ie, including all handles, wheels, straps, etc). IME it often takes a bag sold as a 20" bag to be certain to meet stringent 22" sizers manned by staff who won't "give an inch". (Too many bag manufacturers don't count handles, wheels, etc, when naming their bags by a supposed size.)

Also, some sizers seem to have warped over time or else not been made to exact standards, I don't know what the reason is (sloppy inches / cm conversion?), but they can sometimes reject stuff that technically should fit but is right up against the limit.