No, this is not true and I was going to make the point earlier in regards to sales tax - in the US, airlines must show the FULL price including any mandatory fees and taxes while stores are actually prohibited from including sales tax in posted prices (in many if not most places). Yes it’s a bit absurd. Just like BA’s seating policy.

(Of course the all-in pricing only applies to airlines, hotels still can get away with obfuscating resort fees, and I don’t think anyone would defend that practice.)