> in some ways the Supreme Court is actually our least dysfunctional branch of government right now. So, could be worse?

In a cynical way, I think that them being dysfunctional could actually be better at this point. On one hand, new pressing issues might not be seen, but on the other, no more new damage can be done.

> But they were wildly successful in both creating a lasting, successful democracy, and popularizing the idea of democracy worldwide. It's hard to argue with results.

I agree, the results are undeniable in some ways. My intention wasn't necessarily to berate the US founders, but point out the culture that has emerged surrounding them. It's not that they didn't have some good ideas, it's that people often tend to see them as universally infallible. If one can tie their proposal to something the founders thought (no matter how tenuous the connection is), the idea immediately gains merit just based on that alone.

While a nation like the US going on for so long without major reforms in its democracy is a commendable thing, the often-unquestioning reverence for anything from the period of its inception has prevented and will prevent people from patching any cracks that show up in the system with age. A government shouldn't ideally rock the boat too much, but it can't stagnate either, history has plenty of examples of both.

> I expect if we attempted to rewrite the constitution from scratch, we would get a worse result, since the rewrite would be dominated by the 90% of conversations that are less lucid.

I think the modern understanding of most of these systems is unquestionably better, the issue that would prevent a better system from being formed isn't just the variety of conversations, but conflicting interests with overwhelming power. The US as it is today was founded by a fairly cohesive and tightly-knit bunch of people (at least, as far as I can understand), in an extremely different world. If the US was given a shot at complete reform today, you would have every major corporation and foreign government jumping in at the opportunity to pull any levers they could reach to ensure an outcome that's favorable to them. It would be a disaster. Hell, even with your example about people voting against ranked choice systems, it's not like all voters are actually informed (or even know anything) about either system. And every time these proposals crop up internationally, there's always lots of marketing in either direction from entities who would really like one outcome. Hence, the people tend to stay conservative and vote against changes.

If we got a panel of experts (or even just any sane people with a cohesive and compatible set of ideas) together, I think that today we have enough information to create systems that are vastly superior to either. The EC was created to address certain problems, but to me it seems to have interrupt the natural power of a vote too much and make the election system too prone to swings led by immensely tiny margins. But yeah, it wouldn't be strictly democratic in the sense that anyone could offer input - but neither was really the inception of the US, most people just chose what they perceived as the roughly better option as a package.