Doctors, nurses, teachers, and even architects need to have continuing education to continue holding licenses to practice. My father was a NYS registered architect and had to accrue X hours of training per licensing period or his license would be revoked.
So from that standpoint alone, I don't see an issue extending that to gun permits.
And again, being able to service your weapon in front of an inspector as part of that seems reasonable. Lost a co-worker who was cleaning his gun, which was loaded, and it went off. Had he been through some sort of refresher, maybe that accident doesn't happen.
Ah, but medicine, engineering and even teaching (think AI) are constantly evolving and changing, so those folks need refresher courses and perhaps testing or certifications.
But owning and operating a firearm isn't like that, although laws may change, so owners need to be aware of such changes (like the recent removal of a carry permit in Florida).
Owning and operating a firearm seems to me to be more like owning and operating a vehicle. Basic proficiency doesn't need to be constantly tested or recertified. Those who take high performance driving courses are certainly better drivers than those who don't, but being super qualified isn't necessary to drive.
Here in Florida, there is no retesting required, other than the usual vision test for driver license renewal. The same for firearm ownership. A Colt 1911 will operate the same way that it did 113 years ago.
Aspeck made some great points about US history in Post #55 and I'd like to add to that.
The "United States" is literally a union of 50 independent states, or mini-countries, if you will. So, each has their own laws and rules which affect the citizens in those states. And they can be very different; e.g. Pennsylvania, New York and Californian are worlds apart from states like Florida, Kentucky, Tennessee and so on. And citizens and can either work to get the laws changed in their state to match their desires, or are free to move to a state with completely different values.
One other point... owning and using a firearm is a tremendous responsibility and if used erroneously, the owner should be held accountable.