.38, .357, 9mm, .45 ACP, .45 Colt, .380, .22RF, .44 Spl & Magnum.....
(I may have forgotten a few and thus missed them)
So, what do all the rest have to offer that these can't provide?
(I'm wearing a flame-proof suit)
The .40 S&W offers a more powerful round in a higher and bigger caliber in a 9mm size and weight platform (unlike 10mm) without sacrificing much capacity (unlike the 10mm). 40 S&W is also cheaper to shoot than 9mm and 10mm. You also have the benefit of shooting 9mm and .357 SIG out of a 40 S&W platform, and you can shoot the cheaper 40 S&W out of a 10mm revolver platform.
10mm is basically a 357 MAG for semiautos. It's for those who want the power of .357 MAG on a 1911, striker-fired, etc. semiauto platform with higher capacity, different triggers, and faster reload. It's more of an outdoorsman caliber and .40 S&W is more of a EDC conceal carry caliber against humans (similar to 9mm but more powerful).
.357 SIG was meant to be a duty round. It's a knocked down 10mm (or 40 S&W) casing with a 9mm bullet. It has much more velocity, muzzle energy, and is flatter shooting at distance than 9mm and .40 S&W; however, it's downfall is that it cost significantly more to shoot than 9mm, .40 S&W, and 45 ACP.... The .357 SIG platform can also shoot 9mm and .40 S&W with a conversion barrel.
With 30 Super Carry, it's better than 9mm, IMHO. You get 9mm ballistics but with 3 more rounds of capacity. It should be more popular than what it is, especially over 9mm. The issue is that NATO, L.E., most Americans, and ammo companies are highly invested and emotionally attached to 9mm. The ammo and firearms options for 9mm are seemingly endless. Plus, it also help that 9mm is cheaper to shoot because it's a popular NATO, L.E., and civilian round. That said, it doesn't change the fact that 30 Super Carry is basically 9mm but better because of the 3 extra rounds of capacity in the same 9mm footprint.