Is the Lifecard Credit Card pistol worth having?

There are some talk among CCW about having a backup to their primary handguns.
But how many actually have a backup to their primary handgun?
I know most are not LEO’s, but packing more heat is always better than not having one at all.
Trail Blazer Firearms from Ashville, NC sells a tiny single-shot .22 LR pistol that is the size no bigger than a stack of credit cards. When unfold the handle chamber can house 5 22 rounds.
YouTuber Big Daddy Hoffman 1911 had a chance to try out the LifeCard Credit Card Pistol. It’s small enough to fit inside the change pocket of your jeans.
This little thing unfolds into a single-shot pistol.

Big high thumbs up in the concealment catagory.
You probably won’t win many gunfights but as a backup to your primary backup (ankle gun), guess its better than nothing. Sort of like a last ditch Jame Bond 007 effort, this little pistol might be useful for that purpose.
With a price tag of $399, is this just another fad or is it something useful to have? Would you get one?