> Firstly, regulating a thousand small players is much harder than regulating a few.

I don't agree with this.

Get you and a thousand friends to submit fake mortgages documents and let me know how many of you end up in jail. Compare that too how many people went to jail from Wells Fargo.

More smaller players is easier to regulate because you can literally use any punishments. If you dissolve Wells Fargo the economy is going to throw a fit (see Enron) but if you dissolve a tiny company then nobody cares.

Real Estate and Healthcare seem to be pretty highly concentrated industries imo. Even though there are a zillion agents/doctors they're part of a professional guild and that guild does the lobbying on their behalf. Like good luck getting antibiotics on your own but after a doctor looks at you for 1 minute you have a prescription for the same drug you always take for an ear infection.