I never had any checkups during my youth. And no one in my age group did either. I was born in 1964. I recall going to the doctor only when my school required it. Usually for 5th grade and the start of 9th grade (which was our high school - grades 9 -12). Unless you were really ill you never went to the doctor.
My mother was a nurse so that may have had somthing to do with my case, but none of my friends ever went to the doctor as routine as far as I recall.
Our school vaccinations were given at “health fares” at the school. You’d bring in your permission slips and the whole class would go to they gym and be vaccinated.
I don’t know why they call them “well” visits, but I can attest that they do pressure you take them in for “well baby” check-ups and “well child” check ups on a regular basis. For babies, it makes sense because they have to get shots at certain intervals, then it goes down to once a year. They make you feel like you don’t have a choice. They tell you when the kid is “due” for her “12 month well baby” appointment and the like. Our insurance pays for them, and I love my kids, so I go along with them, but they probably aren’t as urgent as they make you feel.
As children, my sister and I visited the pediatrician annually for checkups. This continued up until we were each 18. I well remember my last visit to the pediatrician at age 18–sitting there, in the waiting room, surrounded by stuffed toys and picture books; having arranged to meet the guys at the pub later. It was a little weird. But Mom insisted that we have an annual checkup with the pediatrician, no matter how well or ill we were.
That probably isn’t as universal as baby checkups. At least, I’ve never had annual checkups as a grownup - maybe I’m just weird. But I don’t know any parents who don’t take their babies for their monthly/3-monthly/yearly (depending on age) health nurse visits.
I remember having checkups as a kid (70’s) but they didn’t last past primary school age.
The regular well child visits pretty much end prior to school age. After that, there will be one or two visits for immunizations prior to beginning a particular grade in school and any physicals required by camps, sports teams , etc which may amount to an annual visit for some kids, but not all.