But if my friend Jane is more intelligent, more informed, and less ideological than I am, it seems like voting however Jane is going to vote is a strict improvement over voting however I would naively.

No. You're missing a huge component: values. Political choices are typically between conflicting sets of values or between competing interests of social groups.

Debate rages endlessly between pure capitalists and those who want some socialism thrown in.

What exactly is a "pure capitalist"? This is a strawman frequently erected, but there seems to be a major absence of real people with views that can be described as such.

when we can't take it any more.

Who's "we"? Society is heterogeneous. Some want redistribution right now, some would never want it.

If the average government official is smarter than the average member of the populace, it's potentially a win to have the government make decisions for population members.

Again, no for the same reason. Values are hugely important and you're ignoring them. Besides, government officials have their own incentives which do not necessarily reflect the well-being of the population. And, I hope you have heard that power corrupts..?