Of the Australian boot makers left, there is Mongrel, Redback and Rossi.
Rossi is having real problems with covid right now stocking. I did not like how narrow their toe box is, because one of their models gave me a Mortons neuroma. Their Booma that was a favorite because it doesn't have the chunky ass sole most the others do. A lot of Rossis designs use a plastic rubber nitrile outsole with polyurethane foam on the midsole for comfort.
All 3 makers are subject to hydrolysis since the other two makers use polyurethane and thermoplastic polyurethane (tpu) outsoles.
Redback is the most well known. Their boots have the most comfortable design boots I've possibly ever tried. Problem is they've expanded in the last 5 years, and while I've seen people's Redbacks last 10 years, they've either switched PU compounds or they are overproducting boots so that some sit on warehouse shelves for too long and the foam starts to breakdown due to unuse with hydrolysis. Check
productreviews.au or whatever to see how every complaint seems to meet the same criteria, I bought these boots and didn't wear them till 9 months later, but when I did the sole broke off. I will also add that while the tread of the tpu outsole is deep, it has a few problems: certain rocks will eviscerate it, the spongy gaps will eat pebbles like nobodies business, and it's not the best under slick circumstances. I took a slip down stairs with a pair of slipons, that sent me down their respective flight and if there wasn't fencing at the bottom edge of it, I would be dead or broken today since I was 80 feet off the ground. I still wear their Everest, which I think is one of the best boots today.
Mongrel is similar to Redback. Their sole is very chunky. They rank the best on
productreviews.au. they are well known for their side, zip boots as a better mix between pull ons and the time it takes for lacing.