If you read the article, most of the decline in gas consumption in Australia is from changes in industrial usage. Residential demand is only down by 6% and part of that is likely due to the effective ban on gas in new residential construction which started in 2023 in Victoria. Prior to 2023 residential gas usage was increasing.
It would be useful to know if the industrial use is factories replacing their use with other sources (e.g. I have read that food manufacture is switching to electricity in Denmark, although it can be held up waiting for a grid connection if there's a data centre ahead of it).
Or, did they improve their efficiency.
Or, have they closed.
It has a whole section on the impact of power policy though and 15% of power mix to 7% for gas is significant. Coals fall is notable too.
Australia never had much residential gas usage. Mr he very vast majority of residential homes don’t even have gas. No need for a furnace.
A 50% price decline doesn't imply there's 50% less demand for petroleum. If 6% less demand is all the margin consumers need to get their supply, then price can drop quickly. It's all in the margins.