Too bad John Browning didn't think to loose that stupid rim back in 1929 and headspace the case on the mouth instead of the rim. If he had I think the Super would have been equal with the .45 in popularity.
You can't blame John Mose for that rim, since he died in 1926. From what I understand, he designed the .45 ACP to headspace on the case mouth after seeing the 9x19 Parabellum. Prior to that, everyone tried to headspace auto pistol rounds on the shoulder, in the case of the 7.63 Mauser, or on a semi-rim, as in the case of the .38 ACP.
The semi-rimless .38 ACP case was similar to plenty of other 9mm cartridges. The 9x19 was sort of a freak in many regards, as most wanted the slightly longer cartridges. However, since it was adopted by the German army, many people went for it. Since it could easily feed in sub-machine guns, it soon became the most popular 9mm pistol cartridge in the world. Not the best, just the most popular.
Most of my .38 Super barrels date back to the days when they tried to headspace on the semi -rim. Not sure when Colt changed to barrels which would headspace on the case mouth, but I bought a Gov't model in 1984 with the old style barrel. I soon learned to seat the bullets out as far as the magazine would allow.
9x23mm is a good cartridge, but is handicapped by its ability to accept heavier bullets. I have loaded 147 grain Hornady XTP's with good results. I have loaded several .357" bullets in the .38 Super. As mentioned, this gives good results. I stopped at 160 grains though. Never tried a 180 grainer, perhaps I need a new project?