Is there collaboration between cyber criminals and banks?
The vast majority of cyber crime is fraud. The criminals don't hack the bank directly; rather they hack the customers of the bank and commit fraudulent transactions.

I strongly doubt there is active collaboration. Some criminals may have insider contacts, but that's different to a symbiotic relationship.

There may be an effect somewhat like you mention. Increasing security is expensive for banks, so it is only worth doing if they are experiencing a certain level of losses. In theory it would make sense for criminals to restrict their level of activity, to avoid banks implementing additional security, which would make their job harder. In practice I don't think this happens, because their are multiple cyber gangs and I strongly doubt there is a gentleman's code between then.

It is theoretically possible for someone to hack the bank itself, and directly modify balances - effectively creating money out of thin air. In fact, it is thought that some major nation states (mostly US and China) have penetrated many banks around the word. However, if they started to extract money, this is likely to be noticed, due to internal checks and balances. It is more valuable for these state-sponsored actors to silently remain present, capturing information. And one day, perhaps they will strike, as part of a larger war strategy.