Hotels and some things are a huge mess.
But generally your random consumer buying a random widget has some idea about what taxes are involved and roughly what to expect when they buy specific consumer goods / the machine tells them what to pay.
It's complex if you want to do the math and get the exact number each time, but for most transactions it's a fairly small amount / not something you need to think about / need to know the exact number.
If I go pickup a burrito I'm not worrying about if it is $10 or $10.25.
If I wanted to worry about that it is possible to figure that out without knowing all the taxes myself.