Fun topic. I wouldn’t do it. BUT some gun is always better than no gun.
However, if I did carry .22 it would be a pocketable double action revolver. I would want to be able to pull the trigger on a new round if one failed (like others have said, happens occasionally with 22).
The problem with 22 is if you really want to poke holes that will stop a bad guy, you’d probably have to aim for a CNS shot. (Not to be gruesome, but it’s true). That could be a difficult target even with 22.
It would be better to have a larger caliber and aim for center mass.