This is why a bunch of people wouldn't sign the Constitution without the Bill of Rights. I don't think the initial form of American government was supposed to last this long. I think the framers thought that eventually the system would fail, and they wanted the populace to be free in a way that would enable them to dodge tyranny in the aftermath of government failure. The idea is essentially that free people would continue to demand freedom, no matter which kind of government organization came out of the next Revolution.

I think they imagined revolutions would be a more frequent thing, like France or something.

People tend to focus on the 2A as the core of freedom, however I'd argue that our other freedoms like association are more fundamental for resistance to tyranny. The entire package fortifies us.