

The lower house single-member electorate voting system does still favour larger parties, it’s just way, way, better than FPTP.
https://oercollective.caul.edu.au/aust-politics-policy/chapter/electoral-systems/
Relevant part starts at “Majoritarian (or ‘winner takes all’) systems” about a third of the way down.
Unless Australians are comfortable with sending a much larger number of lower house members, that would make the electorates get much bigger than they currently are, and I would guess removing local representatives would not be a popular move.
I’m not entirely convinced that 1 liberal and 1 Labor would be locked in everywhere. I think the change in electoral system would produce governments much more representative of how people vote. It would change us to a system where forming a coalition is practically expected.
5 does seem like a reasonable working number of members to send as a combined “delegation” from an electorate, but that’d be the maximum desirable, in my view.
With 225 members and sending 5 from each electorate, that would reduce the number to only 45 electorates in the whole country.
Something, I’m totally fine with, I think federal electorates ought to be much larger than state or local electorates, but it would probably be a hard sell to many people.
Really appreciate you sharing your thoughts on this :)