People are resistant to change - like inertia - but if pushed enough, they will. Burger King & Wendy's only went up 55% whereas McD went up twice that at +100%. McD could have kept their prices flat and gained business from them, remaining within their brand as the "cheap fast-food" option, but instead they seem poised to lose it? Well, I guess we will see.

Yeah, it is scary to see just how evil they - b/c with profits like you showed, they did not have to increase them all, so the fact that they not only did but did by that much is somewhat shocking.

We're also in a society now where 2 people or 2+jobs are REQUIRED for a "normal life" unless you're a tech or finance bro. People just don't have the energy or time to cook, fast food is often "on the way home" and saves well over an hour and effort.

I'm "lucky" that I'm single, in that I can cook a weeks worth of food in one day and there's no one to complain about "this again?" In literally every other respect being single in this society for over a decade sucks.

so people that frequently go to McD will still go

Right there.

Double your prices, lose 49% of your customers - you’re winning. And restaurants are less busy? Fewer staff needed? Winnning ($$$$)