If your reaction is wondering if this is legal then you should be interested in the passing of new laws that make it unequivocally legal. Society should be able to govern itself.
> Guests in California will see a fee-inclusive total price—before taxes—on all listings.
https://www.airbnb.com/help/article/3610
https://leginfo.legislature.ca.gov/faces/billNavClient.xhtml...
Now they just need to fix that part.
Case in point: cost breakdown from the invoice of an online order a few months ago (with the dollar amounts removed):
> Subtotal
> Shipping (Economy)
> Tax (Solano County Tax 0.25%)
> Tax (Vacaville City Tax 0.75%)
> Tax (Solano County District Tax Sp 0.125%)
> Tax (Solano Co Local Tax Sl 1.0%)
> Tax (California State Tax 6.0%)
Once your address is known taxes can be calculated. At what point is an after-tax final price to be shown? On an ad? On a targeted Ad? Once you reach the storefront based on unreliable geolocation? (which would be wrong for me, because geolocation bundles two cities here together as one) Once you create an account? At the checkout when you've specified the shipping address? As things tend to happen today, its usually only at the last step.
As much as I'd like to see it, I don't see much chance of improving the visibility of final prices without comprehensive systemic tax reform first.
The obvious quick solutions aren't exactly fair in the current US system. Imagine a "quick fix" of requiring the vendors to price in-a generic taxes for everyone. Just like with credit card system fees, "simple" fixes like that that benefit the residents of high-sales-tax states to the detriment of no-sales-tax state residents. While such a system would work for physical stores, they would get hammered if they had to prices on the shelves or signs that were higher than online prices.
As much as we all want a fair straight-forward system, I don't imagine it happening any time soon in the US. There are way too many unresolved zero-sum political fights and ideological differences standing in the way.
It certainly can be done (eg: Australia) but the circumstances there were very different.
My guess is the only solution (and it would suck and be met with much resistance) would be to make all the taxes based strictly on where the seller is, not where the buyer is. Then the buyer would have to be on hook for use tax instead of sales tax. States would not like this because most people skip paying use tax altogether.
Or just get rid of sales tax as a thing, and if you want localized taxes put them on property. That's what my state does (plus income tax).
I agree that we're unlikely to see any sane solution in the US in our lifetime.
Short of that, ban sales taxes levied by local governments; only allow states to levy them. It's easy enough to figure out which state someone is in.