Even smartphone demand slows down. And that's a device with daily utility with a 2-5 year life.
Seriously, I'm coming at this from a perspective of a country boy who went shooting 3-4 times a month as a teen, and earned a bounty for shooting pigeons on a farm. How much more demand can be filled for more guns the mostly sit around and gather dust? It's a market driven by ignorance and fear -- folks are treating these things as investments for a doomsday that will never come.
I'm not an anti-gun guy... I own two shotguns, a hunting rifle and a .22. What's the point of adding more? Pistols, AR-15 fetishization, etc aren't for me. What I have will probably be in great shape beyond my lifetime; if anything I might trade up if I got into skeet again.
Say you are right and no regulatory changes take place.... you're still going to have a cohort of old people who hit the gun hoarding profile start to die off and flood the secondary market with estate sales. My parents have a neighbor in the country that probably has >250 rifles, and there are way more people like that than the WW2/Korea generation that has mostly left us. What's the collector value of yet another AR-15 clone?