On the subject of dodgy professionals, Dentists are up there with the worst,
anyone remember the corrupted NHS drill & fill crimes of the 60s and 70s.
The dental abuse they willingly inflicted for monetary reward was a shocking violation of their hippocratic oath.https://youtu.be/YoWom0CCRKM
Being "a professional" often brings a bit of power, in the form of an authority on certain matters. As we know, power can corrupt.
But only absolute power tends to corrupt absolutely. Many professionals are subject to ethical standards imposed by their trade union (although they prefer the petit-bourgeois descriptors such as The British Medical Association or The Law Society). Such ethics, as well as an often professional tradition to do good (or no harm, at least) mean that not all professionals are naughty. In fact, the majority I've encountered of the more traditional ilk have been very honest. (Some are inept, mind).
Sadly, the professional trade unions have a bit more power still than their members so they too can be corrupt. Many naughty goings-on are swept under the carpet or otherwise forgiven by "the professionals" trade unions. Consider those higher echelons of various organised religions, who can be very hypocritical concerning the one rule for "you" and a different rule for "us".
Other "professionals" have no such ethical bodies of any meaningful kind. The City is full of "professionals" who are very good at insider trading, asset-stripping, tax-dodging and all the rest.
Others place a "professional" badge on their little chests despite being cowboys of no expertise other than ripping-off the gullible. No ethics of any kind apply here. In fact, even the law seems irrelevant to the cowboy. "Financial Advisor". Ha! Psychoanalyst. Made-up stuff of great cost and no utility at all.
Sadly, all humans have devils as well as angels advising them as to how to behave. Even you! Even me!! I try to exorcise mine regularly but they're still lurking, I know. Some seem to have gone orf to live in that London, where they are always welcome.