There has been a deplorable profusion of dark patterns in restaurant checkout UIs, such as offering preselected tip amounts set along a 18-20-25% scale (standard used to be 15%), making it quite difficult to leave a custom tip, etc. Add to this various "surcharges" and other mandatory fees added for this or that (my favorite: mandatory "resort fees" for hotels - seriously why is that not just rolled into the price of…
That's one nice thing about living in the EU, that it mandates full price disclosure for some industries. (Anyone got a list?) In particular, when it says your airline ticket is NNN€, you will pay than NNN€. No screwball fees up the wazoo.
[1] https://ec.europa.eu/commission/presscorner/detail/fr/MEMO_1...