I think one of our greatest failures as a species is the hubris of _thinking_ that we can "architect a society"

The organization of society is not outside our control. We've been architecting society for 1000s of years based on what has worked and what hasn't in years past. We aren't just along for the ride although that is a convenient excuse to do nothing and make no effort.

I wasn't necessarily suggesting to "do nothing and make no effort" - That's a strawman and false dichotomy. Sure, we can generally try to do more of what works and less of what doesn't. But usually the type of people who want to "architect society" end up being the worst type of "rules for thee but not for me" tyrants.

I think the Founding Fathers of the U.S. 'architected society' reasonably well in the 1770-1800 period?

Tip-of-the-hat to our founders, for sure! But I'd say they were architecting a government, not a society. That's a very important distinction, and without it you can end up with some really destructive Statist/Authoritarian stuff.

Regarding those first 25 years or so: Jefferson's attempt to ban slavery in 1784 failed by 1 vote. Then there was the Whiskey Rebellion in 1791 and then the Alien and Sedition Acts of 1798. So, nothing's perfect I guess...

I highly doubt they ignored considerations of how their envisioned government would affect future society and vice versa.