There are a lot of things we can improve, though. First past the post voting systems mathematically guarantee polarized two-party systems aligned on emotionally charged but relatively inconsequential issues. So we should switch to approval voting.
Having the same person purport to represent our interests in everything from which soda sizes we're allowed to drink to whether we can make our own end-of-life medical care decisions leads to incompetent science denialists running the government's science committee, gross ignorance of the consequences of their actions w.r.t. encryption, etc. So we should design a system with separate representatives for each technical domain, combined with an optional directly democratic override on a vote-by-vote basis.
Etc.
These problems pop up with my example:
* You still need someone to centralize the execution; people are going to want a hierarchy and to have one person at the top.
* Having 5 mayors means paying 5 times as many people (but they'll be able to work much more in depth in their subject area)
Actually, it seems more recently the trend is to do it; and then make it legal retroactively.
One of the problems is that we can't figure out a better system of using humans to govern humans. Do you think we'll ever develop the fabled Sci-Fi computer overlord to govern us? Will it end in the traditional "disaster of ignorance", where the members of society return to a child-like state, and are unable to maintain the great machine we've built?