If Qantas or Virgin had anything like a monopoly, there wouldn't be an Air North or a Rex.
Rex in particular has proven that if you pick the right market, by in their case, combining two previous regional carriers into one, giving them scale, then take your time and move into mainline flying on trunk routes, you can build and expand a sustainable business.
I'll have a pint of whatever you're smoking. Air North operates in places QF don't really care about because its just sand and flies, and Rex only exists because the previous government handed them ans QF a dumpster full of cash during covid to maintain regional routes, that they spunked on jet operations.