It's so weird, as I had a very near identical experience. I went through a cursory checkup then they sat me in some waiting room with a video on all sorts of dental diseases, apparently all of which I had. They needed to drill out some half dozen cavities, carry out a root canal, and I cannot even remember all what else. I noped out without even asking for a quote, and started skipping my annual exams.

Some 20 years later I finally went to a dentist again, in a developing country no less, because I had a visible cavity - my first ever. It was quite scary given the elapsed time. $15 dollars, and about as many minutes, later all was said and done, with no other issues present.