Definitely as a millennial I’m of the last generation that will remember arranging to meet up somewhere in advance and sticking to that plan (or rearranging over landline with more than a day’s notice…)

This is related to an interesting phenomenon I noticed while chatting about this with my parents. The question “where are you?” was hardly asked back in the day. With landlines, you already knew where they are. The only time that question was asked involved payphones. And those barely exist anymore either.