The monarchy is part of the British heritage that has enabled Australia to be a strong, long-lasting democracy and an attractive destination for immigrants. There's no reason to degenerate the country's culture by replacing this impeccable and impartial leadership for a politicians' republic — especially not when the main argument for that is based on assumptions about the rising population of Chinese and Indian immigrants.
Replacing the British monarch is an important move for Australia. It would give all Australian voters a merit-based choice about who speaks for them as head of state — reflecting Australia's maturity, independence, and unique identity. The decision will be in the Australian voters' hands, unlike now, where it's luck of the draw of who's representing the British Royal Family.
There's a 72% chance that Australia will hold a Federal Referendum on an "Indigenous Voice to Parliament" before January 2026, according to the Metaculus prediction community.