While I mostly agree...

Venice was run by very old men. It was common for the Doge to be in their 80s. Meanwhile, many of their neighbors had kings who were very young, sometimes teenage boys.

Venice was the longest lasting, most stable state in Europe.

That might have as much to do with their insane system for choosing a Doge, which many historians think did a lot to force compromise and reduce corruption.

They took the full council, selected a random subset, had that group choose another group from the full council by voting, then repeat that random selection followed by voting another few times ending with a final group who voted to select a Doge.

There's multiple states in Europe that lasted longer (and they are still lasting to this day) than Venice.

The Doge had no power.

Welcome to my rathole: Venetian history. To expand on your thesis, the Council of Ten was the executive power in Venice, but the Doge and minor council attended the Council of Ten meetings and the Doge often chaired those meetings. And even if he was powerless, the Council was made up of other old men. I don't want to push this whole argument, I'm not recommending we adopt the Venetian constitution. But I don't think you can blame current chaos on age.

There is another variable, the rate of change. When a Venetian Doge was 80 years old, the world was.. more or less the same as when he was 20.

Contrast that to now, where an 80 year old in his twenties likely did not even have colour TV.

Can you explain how is the example of Venetian republic relevant for something like a massive multi-cultural, multi-racial federation in 21st century? One that's led by 100s of old people not just ten rich family heads?

It may have been stable and dominant in spite of that, like America, currently being run by senile old men. The human mind is a biological computer and it isn’t pretty the older it gets.

https://medium.com/psyc-406-2015/how-fast-does-iq-decline-ca...

Average is probably not what you need to worry about: I'd bet David Attenborough and Mel Brooks still have IQs considerably higher than the average 25-year old. And I'm not convinced IQ is as important as that elusive factor called character.

But you may be right. Maybe what the US really needs is a lagoon.

Well at the times of Doges the world hardly revolutionized. Nowadays a person in their 80s has lived through the rise of at least three different medias (radio, TV, internet) and the world has never changed so fast.

We're talking about democratic republics. How does the one map to the other?

>Venice was run by very old men. It was common for the Doge to be in their 80s. Meanwhile, many of their neighbors had kings who were very young, sometimes teenage boys.

But those kings were (legally) absolute monarchs, while Venice was (somewhat) a republic. This isn't a trivial distinction. The young kings of the various Carolignian successors also tended to inherit their titles when their fathers were killed, while Venice occupied a highly defensible geographic location (a swamp) which supported institutional continuity.