Is paying upfront really that unusual?

I'm a server in a café in the West Country. It's table service but pretty casual (seat yourself rather than being seated, sandwiches and jacket potatoes on the menu etc) and we take payment upfront.

Is this a regional or generational thing? I would personally expect to pay upfront at fast food places, coffee shops and casual cafes and only pay at the end in restaurants and gastro pubs, but I'm told at least ten times a day by customers (generally but not always tourists, and usually by people aged 50+) that "I've NEVER had to do this before" or "that's so unusual" or "what, even if I'm ordering food?".

Meanwhile I saw a segment on the news (Sky I think) last week about how 1/3 of places in the UK have experienced "dine-and-dashers" and I can only think of a handful of places in my town that charge at the end, so I find it hard to believe that people have never paid upfront before. Is this really so unusual nationwide or is it just becoming more common in recent years?

Edit to add: wow okay, it's unusual! Perhaps it's the number of places that ask you to order through the app that's skewing my perspective a little, but I really didn't think it would be. I personally judge by how upmarket a place is rather than where the payment is taken so this is so interesting.