These sort of choices are probably transitory over the lifetime of a shooting enthusiast.
As a younger man (and avid handloader), I thought that the only sensible, serious handgun calibers were .45ACP, .357MAG & .44MAG.
Those choices remained pretty much the same when I first became a young cop, too.
Over time, I added .38 Spl and 9mm. The .38 Spl because I wanted a smaller revolver for court, meetings, classroom training situations and some off-duty situations (especially vest & jacket pocket carry). The 9mmP, grudgingly, when we transitioned from .357MAG to 9mmP.
Fast-forward quite a few years, during which I served as a firearms instructor for 26 years, and now going on 9 years into retirement ...
My most commonly utilized CCW calibers are ... .38 Spl, 9mm & .380ACP.
Sure, I still give my .40's & .45's some range/trigger time. I grabbed my stubby CS45 (3.25"/6rd mag) for my last LEOSA qual, along with one of my M&P 340's. My .40/.45 weapons still see belt time, in addition to range time, including use for long road trips as occasional LEOSA weapons, but it's my smaller & lighter options, meaning .38 Spl, 9mm & .380, which see the most common retirement & LEOSA use.