I really enjoy shooting my Walther PP in .22LR - except for loading the magazine.
Unlike the Ruger MK I,II, and III series, the rounds in the PP magazine are fairly level, so you have to take a great deal of care to ensure the rim of the round you are loading in the magazine is placed in front, and stays in front of the round beneath it. If not, you'll end up with the rim of bottom cartridge locking the top cartridge in place so it can't feed.
Bill Ruger used a very sharp up angle for the rounds in his Mk I .22LR pistol (and all subsequent variants) magazines, for exactly that reason - the sharp angle ensure the rim of a cartridge always remains in front of the rim of the cartridge below it.
My CZ75 Kadet and my Kimber 1911 .22LR also use magazines where the cartridge is angled upward, for the same reason.
----
When you start talking double stack magazines where the rims are now staggered, the rims are now engaging increasingly farther out and up long the sides, complicating the problem of keeping the rims of the upper rounds in front of the lower rounds.
Then you can add the problem with the taper needed to accommodate the rim. To accommodate both you end up with a very curved magazine with very sharply angled rounds, that then have to level that angle out on the way to the chamber to enter the chamber cleanly.
Anything is possible, but getting it right is not easy, and getting it right in an inexpensive and easy to produce magazine is a lot less easy.
If you look at the Kel-Tec double stack magazine they address that by having alternate rounds feed on alternate sides of a "fence", that prevents the rims from interfacing and overlapping. That however also required separate guides for the noses. It works, but it is wide, especially for a .22 rimfire magazine and that's not always amenable to some designs.
