Airlines are required to do it [1], it's time to force lodging to do it with legislation. These sites will not do it otherwise.

"You can always count on the Americans to do the right thing after they have tried everything else.” -- Winston Churchill

[1] https://www.transportation.gov/individuals/aviation-consumer...

Yes because AirBnb hosts will surely follow the law and local ordinances this time…

Your recourse is against Airbnb proper if they do not abide by federal statute or FTC rules. Hosts will have no choice in the matter.

How has that recourse worked on the local and state levels so far?

No, because they’re not the federal government?

the airbnb.com.au version does because AU law requires it.

I use it to search in the US as it’s the only way to know all in cost, which the US version always tries to obfuscate