I've been carrying .40 S&W since 2019 which suits its purpose as a self-defense round.
Previously I carried .380 ACP, which I felt perfectly confident in and still believe is a viable self-defense cartridge, (to this day I carry a LCP as backup) but after wild animals started wandering out of the woods surrounding my residential area, I decided that I wanted to carry something more powerful, and there were a ton of cheap .40s on the market. Since then, I've grown extremely fond of the cartridge, hence my username.
I don't see myself upgrading to a more powerful cartridge because based on my research on the subject, once you step beyond common duty cartridges like 9mm Luger, .40 S&W, and .45 ACP you start to get diminishing returns as far as effectiveness against humans goes, then the probability of overpenetration increases as well. I just got a USP45, but that doesn't mean that I'm going start carrying it loaded with .45 Super, because I don't live in Alaska, the biggest animals around here are black bears, and it's excessive against humans with no real benefit.
Practically all of the common self-defense cartridges are viable for self-defense and the differences in terms of performance between them is marginal since they were all designed for the same purpose. So unless you're concerned about running into something far more fierce than your average thug, emaciated meth addict, or crazed 20something shooter who has decided to blame whatever establishment you happen to be standing in at the time for their misery, whatever it is that you're already carrying is most likely adequate.
If there are other threats like wild predatory animals who are particularly hardy in your area, then you should probably consider stepping it up. Otherwise, stick with whatever you're already carrying and have learned to shoot proficiently.