Like, I don't think it is the right lesson to say that the higher price points scare away people in the abstract, as if everyone who is eating is paying the meal plus 15% and they are just being dumb by not realizing they are paying "the same" in a world where tipping doesn't happen. (edit: And yup... I now see other comments leaning into "Americans are bad at math").
It isn't that uniform: a lot of people tip 10% while many are tipping 20%; there are people who aren't tipping at all and people who routinely tip 30%... and it doesn't stop there! There are also people who at least occasionally throw in some massive tip... I myself have, for various reasons that made sense at the time, thrown down a >100% tip on small checks.
Sure, some people like the awkward "control" over the wait staff, but that is also simplistic: there are people who make it a status symbol and proudly are known among their friends--the wait staff doesn't matter--as "big tippers"; and there are people who get into friendly competitions with their friends over who tips the most.
The result is that this turns into a kind of "pay what you can" at best and an awkward gamified mechanic to force people to stretch to pay more at its worst, resulting in people who have the money to pay subsidizing the people who don't, which maybe is actually a good thing? If nothing else, I see why it is profitable, even if customers ALL kind of dislike it.
(It also, though, causes people who "feel the weight of society" and feel a need to tip to ensure people get paid to subsidize the people who have the money but are selfish and don't give a shit. My guesses as to the balance of people who don't tip much because they can't and those who don't tip much because they won't affects my personal feelings on whether it is "fair" or not.)