Check out the government program called Choke Point! Or ask a gun dealer or pawn shop who lost their banking relationship.
As someone who has dealt with this up close and personal over many years (back to the Obama era), it doesn't work that way.
These small institutions are regulated just like the big boys. The regulator can shut an institution down, and even if there is not a hard violation, the regulator's wishes/beliefs/opinions are often heeded.
So far in 2024, only two banks have been closed by the OCC or the state banking departments. There are between the FDIC and OCC about 230 enforcement actions issued since 1/1/2022 against banks, some duplicate, for instance, a civil money penalty and a written agreement against a bank. There are about 4,400 banks in the United States. Excluding Federal Reserve or State enforcement actions, less than 6% of all banks are subject to enforcement actions. A majority of them have nothing to do with consumer regulations or the Bank Secrecy Act and related statutes.