Thats not true in Spain as well... i have had complete different diagnosis between different dentists, even in the same office, some trying to up sell a bunch of stuff that i would have to pay out of pocket.
- there are clinical parameters what is OK / not OK and needs treatment, other stuff for upgrading like veneers are in a different bag. But those are good examples: While quite expensive and revenue driving, a good dentist wont try to sell them to you because with prep-veneers the teeth will get "damaged" by taking of 0.1mm from their surface, thus hurting natural material - and a good dentist tries to preserve everything natural as long as possible, unless he/she is a scammer.