In some ways, it's just the four boxes of liberty at work.

The theory goes, there are four routes to "solving" social disputes/obtaining justice in modern societies: the soap box, the ballot box, the jury box, and the cartridge box. They are to be used in that order, because the consequences for society and human life get worse with each one. I put "solving" in quotes because you could argue that the last box doesn't really solve anything.

Right now, at least, you have a large number of people in American society feeling as if social conflicts/injustices are going unaddressed in meaningful ways. I'll let you fill in the blanks as to what those are, but it's not always people who want the US to be like it was in 1955 who are arming themselves. An increasing number of people who are liberal or otherwise practice left-of-center politics, and people who are of historically-oppressed groups, are also starting to arm themselves.

Ultimately, if you start meaningfully solving social conflicts and injustices with the first three boxes, you can avoid the fourth and you'll probably see firearm ownership growth begin to drop. I don't think you'll ever see it meaningfully go away in the US without an effort that few people would consider wise to attempt.