Would be interesting if voter turnout somehow had an effect on the government. For example if the required consensus for new laws would be scaled by the turnout - e.g. for if there is only 51% turnout then any laws that need a majority consensus would need almost all politicians to agree. Could provide interesting incentives for politicians to care about voter engagement and political education.
This is simplistic. Some have simply lost confidence in their representatives and/or cannot find a decent candidate.