I will go back to the FBI testing, everyone can look it up on the internet. For a pile of reasons, they determine handguns rounds mainly just punch holes into the human body. Using that as a base they determined to effectively stop a human threat at 10 feet. Which can or not mean death. A bullet needs to penetrate 14-16 inches. 12 and under won't work, 18 inches is overdone.
Look up the .22lr rounds in gel block tests. I just spend a few minutes looking. I did not go through every test but the Federal punch almost gets there with 12-14. Stinger was 10 another brand was 8. So even if the .22 lr rimfire was a dependable cartridge (as in fires first time every time) as any centerfire cartridge it still ends up short in getting the job done.
What you choose to use to save your life is always up to you. I will use better.
With enough practice and maybe training/coaching anyone that shoots a .22lr handgun great, will become just as good with many more capable guns and calibers. Yep, a hit with a .22lr is better than a miss with anything else, but that way of thinking means to me, too cheap to practice or to buy a capable gun. Myself, if I miss with a 45, 40, 9mm, 357, 38spl or 380 that I may be carrying. I would also miss that shot with a .22lr. It just takes practice/range time.