Yes the auto-loader is what killed the pump, but the price of 22 is what may bring it back if someone was to listen to this idea.
The 25ACP, 32ACP and 9mm are all reloadable and with a pump (or maybe later, lever and bolt actions) you don't loose much brass so reloading those small shells is a realistic option.
Another design that could be promising is the Ithica M37 shotgun, scaled down to work with pistol shells. It could be made even a bit simpler than the shotguns because a loading port can be places in the tubular magazine like we saw on most tube-mag 22s made until the 70s. So the feed system only needs to feed and eject, and no provision needs be made for bottom loading, although it might be a good way to make them to load just like the 37. Who knows. I have not done any work on this yet, so as of today I can't say.
I am hopefully going to make a few of these someday in my shop, but my paying work keeps getting in my way. Making such guns from bar stock is fun, but it doesn't pay the bills.
The 25 ACP would be the closest thing we could get to a 22 LR and still reload for it. I never thought much of it for it's intended purpose (handguns) but as a small bore rifle round it has very serious potential.
50 grain bullets would be very cheap to make and you'd get 140 of them from only 1 pound of lead. 1400 from a 10 pound pot of lead.
Today a pound of lead costs $1.50, so each bullet will cost (today) 1.1 cents.
Powder charges go in the 1 to 1.5 grain range. So the powder will cost about 1/4 cent per shot.
The primer is a whopping 4 cents each.
I think young boys and most men would get all starry-eyed about such a combination.