@lud decentralized governance doesn't mean there won't be any governance at all. There will still be policing, taxes and social services. The difference is that in governing process we will all participate, not only a herd of politicians which decide the fate of everyone else.

Take example the Monero system. When there is a network upgrade it can be proposed by anyone on the forum and if everyone agrees it will get implemented. if there are disagreements they will be put on the table.