FWIW, before Amazon started collecting taxes on 3rd party seller sales you could sort by total including tax when listing all seller options of a product.

The reason it makes more sense to do it for hotels is that many cities have 15+% or $$/night taxes. The highest rate is 20%.

https://hvs.com/article/8911-2020-HVS-Lodging-Tax-Report-USA

In general, hotel and rental car sites will let you display whether they do so by default or not.

I would think it matters more with hotels/Airbnbs than many other goods because hotel taxes can vary a lot when you cross city lines