My wife never had a cavity in her life. We moved to a new state/city and the dentist she tried “found” 4 cavities. We went to another dentist, found none. To this day nearly 10 years later the entire family goes to the 2nd dentist and couldn’t be happier. Long after leaving the first practice their office would occasionally send out promo emails offering sale prices for services. Greedy unethical people exist in all professions.

Edit: Thinking about it further (it has been almost 10 years) I had also gone to the first disreputable dentist around the same time as my wife's initial visit because I cracked a tooth (furthest back lower mollar on one side). They extracted it and wanted to put in a dental implant to the tune of several thousand dollars. Nothing particularly nefarious so far, except that they kept pressuring me about the implant because without it, the corresponding upper tooth would start coming down due to not having a tooth to match up with below it. I didn't do it, partly for the money and partly because I'd heard implants were painful. It doesn't affect my smile or my ability to chew/eat. 10 years later the upper molar hasn't budged one iota.