We do not have functional representative democracies. The material and economic reality of the current system leaves what little democratic practices we have vulnerable to manipulation. There is a power imbalance between our democratic systems of power and the purely economic power structures, resulting in the former being dominated by the latter.
What anarchists envision is not simply the removal of the current powerful institutions, but the replacement of them with alternative democratic institutions. For democracy to survive and function it must be the dominant power structure in a society.