Great analysis. Adversarial pricing/information strategies are offensive and represent a form of cognitive theft from the public. I greatly resent the fact that the advertised price of goods and services in many US jurisdictions is simply not reliable because sales tax is typically not included.
If a vendor wants to display information at the point of sale or on a receipt about how X% of the price consists of direct taxes, I have no issue with that. But having to pre-emptively apply it to every price signal or budgetary allocation adds a non-negligible overhead to the detriment of consumers. Consider a person doing grocery shopping on a limited budget, say $50. Before entering the store, the consumer must mentally reduce the $50 in their pocket to $45 (if sales tax is 10%) and then keep that limit in mind while shopping, in addition to evaluating product value by per-unit cost (which some retailers display clearly and others don't), nutritional content, coupon or discount offers, and much else.
For utilities and many other services, the opacity level rises drastically, making budgeting substantially more difficult. Add in the fact that pre-payment for things like phone plans often costs more than recurring charges, punishing those who try to manage limited or uncertain cash flow with thrift. And the people most likely to struggle with economic insecurity are the least educated.
In other countries where this is not the norm, prices of many goods seem high and disposable income correspondingly looks a lot smaller. But if you see something you want to buy advertised for €100 and you have €100 in your pocket, a winner is you.
A few US businesses take a different approach or clearly signal '$X out the door' on sales adverts, and I try to make a point of thanking them for the practice as well as just giving them my money. I think it's important that they get positive feedback.