My son has a Ruger 22 pistol and it’s a nice piece.
I know that technically for self defense a 22 does not have a lot of potential to stop someone, but it’s better to have something you can and will use than nothing.
And besides, put enough holes in someone and you’re increasing your likelihood of hitting something that could do some damage.
An artery nicked by a 22 can kill just as dead as one nicked by a larger caliber.
There are frangible .22 rounds that do nasty things after impact.