I agree with assault weapons in civilian hands aren't of much use. In fact I proposed my own approach to gun control that would eliminate mass shootings while still enabling citizens to use firearms for defense & sport.

Still, I have some issues with your interpretation of the Constitution. Militia, for example, isn't just a nation's armed forces. And certainly it would be redundant to write a law allowing said forces to be armed. Yet, whatever motivated the 2nd Amendment, let's not forget it mentions firearms not at all. It simply refers to "arms". All too often, today, when effective non-lethal methods of self-defense are developed, state & local legislatures swoop in to ban or regulate them, while the NRA & other A2 advocacy groups are silent.

Then there's the assertion that "people" believed in witches & the Earth being flat. No. I doubt any author or signer of the constitution believed in either. Point being, the document is still highly relevant. Society hasn't changed that much. Some people, for example, acted like shits on 6 Jan. Let's don't make them a majority, or emblematic of Americans & what Americans do.