Firsty, them deciding what is suspicious and not suspicious
Not everybody is an employee working for someone. Some people are entrepreneurs, and as an entrepreneur, you can have some HUGE days. I don't need a bank telling me that my successful day where i made $20k+ is suspicious if I want to withdraw all of it. (people have been arrested for making large withdraws before).
Also, banks freely allowing their customers to scam business (via chargeback). Instead of blindly chargingback purchases and screwing over merchants, visa applicants should be required to take a course outlining the risks of credit cards, and Visa should do proper investigations when a chargeback is brought up.
If a tracking number and proof of delivery can be proved, why should the customer be given their money back?
ALSO, i recently looked into banking investment options. It comes across as a way to just make more money off customers. Think of it like this. It's like it's just them taking your money so they can invest it in polyniex. I only tried it out cause my family (who doesn't know about bitcoins) encouraged it.
Do you have any gripes about banks
That is the way banks operate to make a profit to pay interest to customers, I really like this business model.
They benefit and we benefit when depositing money into the bank. But I think they are more profitable because our money can be used to make a lot of profits, and our interest is only 1% of their profit from our money.

Yes you are right, they benefit when we are placing our money on the banks and that's the reason why they are scared about cryptocurrency, it is because bitcoins can decrease the number of people who will be placing their money on banks and they will prefer to invest on cryptocurrency.