This is because Australia has high internet prices. Partly because it's huge, but partly because the NBN got stuffed-up by the Liberals because they didn't believe the country should be investing in what they called at the time "a glorified video delivery service", so put the tech back a decade, and the country ended up paying more for a worse rollout.

Your comparison point is also a bit weird to me. If I want a decent speed, my choices are fixed wireless NBN at ~250Mbit (400 in theory, 250 in practice), or Starlink at ~200Mbit, and they cost around the same.

If I were just a few km closer to the city I could get 500Mbit fibre for ~$90 a month.

So while it's definitely not out of the range of other plans, I wouldn't say it's definitively cheaper. And I wonder if the recent price drops are down to people not wanting to have much to do with Elon Musk any more. I know it's worth a few bucks a month to me not to be a customer of his.