It is a mix of all the factors you mentioned, but I think the biggest culprit is that many of us view dental visits as reactive rather than preventative. Dental care is often seen as a luxury expense, and with the current economic climate, people tend to prioritize immediate bills over a checkup for a tooth that doesn't hurt yet. There is also a pervasive fear of the dental drill and the potential cost of procedures, which leads many to just endure the discomfort until it becomes a crisis. Personally, I make it a point to floss every night and use a fluoride toothpaste, which has honestly saved me from many clinic visits. My advice is to try and find a smaller, neighborhood clinic that offers affordable consultations, because catching a cavity early is infinitely cheaper and less painful than waiting for a root canal.