I used to believe that was true.
However, several reports over several years of suspects carted off to the hospital after 3,5,7, or 9 hits from a 9mm changed my opinion. If someone is threatening me I don't want a round that sends them to the hospital, I want a round that sends them to the morgue.
The 9 mike mike is the most common round, it’s used by most miltary forces so running out will not be an issue. Same same for .223/5.56 and 7.62. I can carry more rounds of 9mm than .40. Heck, I can carry a brick of .22s in the space of 5 9mm/.40 mags. Weight matters when hoofing.
.22 may be small but most will break off an attack when hit a few times from max range. We are talking about people not Grizzlies.