I don't. People vote against their best interests all the time. The SF housing market is self-inflicted from people voting against new housing, because many of them don't understand the concept of supply and demand.
Neither markets nor democracy are perfect, but at least free markets are efficient.
Or they understand supply and demand perfectly well, and figured out that if they legislatively block new development, fixed supply + growing demand = rising home prices = better investment.
Markets (free and otherwise) work against people's best interests all the time as well, in which case their efficiency is not a virtue.
Big ol' citation needed there
It seems strongly that former requires the latter. Without markets you have a totalitarian state. And black markets. Everyone everywhere wants and needs to trade, for themselves and their families.
The idea of genuine democracy is the loyal opposition. You dochange the government, regularly, without collapsing everything into anarchy.
Endemic corruption will lead to systemic collapse. This makes it worthwhile to vote the best corruption reform candidates regardless of ideology or party.
Democrats have voted Trump, Republicans support Bernie on that basis. It's not completely silly.
Usually due to government intervention.
Corrupt and bloated businesses also "live until they collapse". I trust in democracy more than markets.