A journalist with Reader's Digest famously visited 50 dentists in 50 states and received WILDLY different diagnoses for... the same mouth, ranging from essentially "you have a single cavity you should get filled" to "you need 21 crowns for $30,000", and this was back in 1997:
https://asset.cdocs.com/uploads/forum/attachments/258722/Rea...
It's a fascinating read that basically confirms all of these anecdotes.