I tend to think there are two broad archetypes. The first are the "collectors" or the "hoarders." These are the folks who start with just one firearm, and as their pursuit of what best suits them or simply piques their curiosity at the moment develops over time, rather than discard the older pieces to acquire the newer ones, they keep them. Whether this is done out of "practacality,""philosophy," or "sentimentality," doesn't matter. Some people just seem unable to let things go.
The other group, the one I tend to fall into are "minimalists" or "perfectionists." These folks are the "one pistol, one rifle, one shotgun" types. They too can burn through enormous sums of money, but they do it through cash+trades in a pursuit for what best suits their evolving "firearm philosophy." I went through Berettas, some 1911s, some various polymer pistols, some revolvers, and now only have a couple of 1911s. The pistol style hunt has ended, now I am trying to figure out who is going to build my "favorite 1911." However, a Glock 20 with full caps (if the ban sunsets) or a Para 10mm conversion is whispering to me. I went through a similar rifle cycle, settling on a CMP Garand I am restoring, but I still want an AR for a different niche. Right now I am going through a "magic sword" shotgun hunt. The one for folding knives seems to have ended with a Benchmade 710 Axis Lock. The fixed blade hunt ended with Busse Steel Heart II. I spend way more time and money searching for firearms I want to buy, (except the Garand I have never bought sight unseen), than I do on actual purchases. it took me two years and constant trips to various dealers while handling and field stripping over 40 pistols to buy just one Springfield Champion.
Ultimately, I will probably wind up with no more firearms than I could comfortably carry with one trip to the Jeep. I will never have more than me and my wife can carry in one trip.
Some people have 10 cars, some have two, even if they could afford 10. I guess that is how I am with firearms.
There is of course some overlap, but not too many people own five versions of the same vehicle, though it seems common among firearms owners to own multiple copies of the same firearm.