It's been estimated that about 1% of gun carriers ever take any training other than what's required to get their ticket. It's estimated that in 2019, 6,000,000 people carried a gun daily in the US. Leading one to estimate the number of people who take some formal training with their handgun which would be about 60,000. I seriously doubt 60K people take training but going by the 1% number of those who do seems to suggest just that.
Gun guys= people that carry; people that shoot more than recreationally [ like various pistol matches ]; people who take more than a basics course of handhold, trigger control and sight alignment showing a bare minimum of skills.
It's ALL good, now I'm one who doesn't shoot but once a year when my brother comes down for Xmas, BUT, I've got oodles of time on guns to the tune of 1.2 million rounds through pistols, more high level training on staying alive with a handgun than most will ever attain.
I once stopped shooting for 5 years in the mid 90's. When I picked up the shooting box and went for the first time in that 5 years, the proprioception was still there for all the skills. With the exception of the trigger finger needing more tune up to get to that 5 rds a second again [ 4 per was like oh so ho hum LOL ]
I'm no longer a gun guy, many times not carrying a handgun for weeks during a motor trip with my brother or crossing into Canada or Mexico [ verboten ]. Just taking the PUG 22mag in the tank bag [ which goes every where with me when off the motor.