If the job of being in government was just to ask the people what they want and then deliver it, being a politician would be very simple. In reality people want a lot of things, some of which may be incompatible (lower taxes/better services). We elect people to filter through the noise and make sensible judgements about how we should collectively move forward.

Also, the people who are supporting a referendum led form of government should consider that in most places, the majority of the population would advocate policies which may infringe on your personal liberty. I'm no fan of populism in my politics.

A representative democracy. There's a reason the public generally doesn't vote on the budget and in places where they do (California) it has not gone well.