Referendums and plebiscites are expensive, one-off, seldom, the questions and how they are implemented are decided by the politicians and it is hard to turn them around or revive a failed attempt.
The public is also not used to them. Therefore, the public level of understanding of the process and the issues trying to be solved may be limited.
They can have a low feeling of public engagement.
In summary, referendums and plebiscites try to appease disaffected voters while keeping the political system the way it is.
This can lead to the community venting frustration and anger at the political process through the vote.
This happened with Brexit! 1.2 million people regret their choice.
Instead of making a considered vote on the issue (informed vote), some voters voted in protest against the government (protest vote). It was also used to force a change of prime minister for political purposes.
PD is participatory democracy, a combination of representative, deliberative and direct democracy. You can study and vote on all bills and decisions, gage the way voting is going, assess what you really want and change your vote. PD is an ongoing, voluntary and transparent process, where:
a) You get to vote on the bills and decisions tabled in parliaments and councils, not the Constitution or selected issues;
b) PD politicians are contracted to vote with you. They are bound to vote with the majority of voters in your electorate on bills and decisions in parliaments and councils;
c) You get a minimum 6 weeks to consider and vote on bills and decisions; and
d) You can see the total vote change in real-time as voters vote and are able to reconsider and change your vote.
You feel real engagement in the political process.
What is a Referendum?
At a federal level, a referendum generally refers to votes to amend the Constitution under Section 128 of the Constitution. So it is only to change the Constitution, many issues we face day-to-day are not considered constitutional. States also run referendums but they are generally considered plebiscites under the federal understanding.
What is a Plebiscite?
A plebiscite is a vote on an important public question, the question, the terms and conditions of how the vote will be held is decided by parliament not voters. The vote is also non-binding, politicians may interpret the result differently to voters and can decide how or not to implement it.