This reads like the "essential five" guns we were instructed to buy back in the 80's and 90's. Things have changed since the sunset of the AWB and CCW being nearly universal.
I'd say an AR in 5.56 and a 9mm carry gun are the essentials now. I can hunt, defend my home, and defend myself when out and about with just those two and it still allows a wide latitude of choice. I have also taught my children how to shoot with them. When we got to a public range those are predominantly what we see, too. There is a shotgun facility there and I have seen it used once over the years, and .22 is rarely encountered, even as new clean brass on the range gravel.
I'd say the newer generations aren't as interested in recreational guns as much. They are working, some with two part time jobs, if married they have their free time occupied in other uses. There is also a drop off in hunter licenses sold and that means less recreational guns being sold for that. For the less well off among us in the younger generation, buying a shotgun or bolt action isn't what he sees his friends doing. Nope. It's a 9mm carry gun and AR15/AK or go home.
What do we read here? An older generation griping about the .22 shortage, and retirees are a growing trend, so there is the reason for that. Not the younger guys. Oldsters also have time and disposable income for bird hunting, which is the #1 use for shotguns, not military or home defense. The AR has replaced the shotgun in cruisers, too. Traditional guns still dominate the deer hunting scene but my reality is hunting with a more rugged durable AR does just as well, and arguably safer and better as I have posted for years. The veterans with prior service also have a good working knowledge of the AR and quite a bit of experience with it. The AR is the "Garand" for the modern generation, and sales definitely have shown that after the AWB sunset.
We aren't going to outlaw what has become the dominant sporting and self defense rifle in America. It might be the evil assault rifle in a some locales but it doesn't sell when the PD uses it exclusively. There lie is exposed in every callout.
Nope, there's been a sea change in what the bulk of the gun owning public considers "essential." It's just the older generation clinging to what is familiar who deny it. : ) Glad I'm keeping up and haven't Zumbo'd out.