I would argue That the 1st Amendment was written to prevent tyranny. The freedom to speak out, organize, protest, publish editorials, expose corruption, and petition or speak truth to power in front of interested people is what is supposed to prevent tyranny.
We live in a reality where the media that is supposed to do these things instead promotes tyranny, indoctrinates people, spreads agitprop, suppresses dissent and manipulates the public into accepting tyranny through fear.
You're correct that the Founders feared another despotic ruler, and I don't know if they could have foreseen the dystopian horrors that collectivist leftwing sociopaths have wrought in the last 110 years or they would have added amendments that forbade the federal government from establishing any new form of tax, or spending more than it took in. They may have banned the federal government from establishing any sort of uniformed armed law enforcement.
Let's face it, M-Forgeries and "AR-15's" along with "AK Style" rifles are "military-style semi-automatic rifles" and most bedwetting leftist tumors are terrified of them. That said they're no more of an "assault weapon" than a large rock in a long tube sock when an aggressor deliberately hits a peaceful citizen with it.
The M-14, which in my opinion should have been the weapon we retained until the AR10 was fully tested and perfected was limited deliberately to be semi-auto even though attempts were made to make it full auto. The military issued semi-autos because full auto or "burst" was a waste of ammo. The problem is that the bed wetters will point to 1903 bolt action rifles, and therefore ALL "Bolt Action" Rifles as "Sniper Rifles" if they're allowed to cross that hurdle.
These are collectivist sociopaths we're dealing with. Not "people" who want to create a "safer" world with less crime. Otherwise Jussie Smolete would have already been fucked to death in a Chicago jail, thousands of asswipes who dye their hair with lime kool aid would be facing long prison sentences and Trump would be welcoming Ukraine into NATO while China recognized Taiwan as an independent country.