Back to topic, I think most of scheduled maintenance are just there to make money. ... I don't know but I guess same applies to dental cleaning?
I think that is a good analogy. Dental cleaning. You may not get your teeth cleaned for years and be ok. Or you may have a breakdown in your mouth and take yourself into the dentist for a checkup, and find that the pain is due to a cavity that has been festering into an infection, and now you need a root canal and crown. Repeat on a couple other teeth, and add in a few more significant deep cavities that need to be filled.
The preventative maintenance of a couple hundred bucks a year on cleanings, xrays, exams, etc lets you know what is going on, and things can be prevented or corrected early (ie minor cavity filling, maintaining most of the natural structure of the tooth which leads to stronger teeth and prolonged mileage on the teeth).
YMMV of course. Brush well, floss, etc and you may go years w/o an exam and no problems will arise. Or you just may have a minor cavity or two.
The above story was roughly DW's story. Root canals and crowns cost multiple thousands in our area. And crowns can pop off. The more tooth structure that must be removed during dental procedures, the weaker the tooth becomes, potentially leading to cracks or fractures.
Any dentist please feel free to correct or clarify my layman's understanding of dentistry.
Maybe you could do nothing to fix your teeth over the course of a lifetime (short of emergency extraction if it was REALLY bothering you), and just get a set of dentures or permanent implants at age 50-60 as needed. Wonder what the discounted cash flow looks like on paying for implants when you are 50 vs. paying for preventative maintenance and the occasional remedial procedure as you go along. Of course you have quality of life and aesthetic concerns to worry about - strong healthy teeth are important to me at least. Much like having a car that continues to run well and runs efficiently.