No -- you are making the assumption that a cash-only existence is possible for large criminals. If what you say is true, then money laundering would not exist, because it would not be necessary.
That's exactly what I'm saying. It isn't only possible; they do it!
Money laundering directly through a bank is unnecessary and stupid. The criminals that end up on the news are the stupid ones who
thought it was necessary.
But it does. Drug kingpins have so much cash it is quite literally a problem of size. After paying all their flunkies, and buying illegal guns and such, they are still stuck with bales of FRNs. That's why the Feds target any place that might accept large amounts of cash for legitimate items -- cars, houses, boats, non-illegal businesses.
You are still thinking too small. Large criminals simply start their own factories to manufacture arms, cars, and boats. They launder through businesses, not banks! Once they are large enough, they lobby (aka "bribe") politicians to protect their operations through legislation/turning a blind eye to it all. I can provide many examples upon request.
I've seen many city blocks of construction in Moscow that was all built with drug proceeds. The cash was paid directly to the construction workers. (Where is the bank? I don't see one?) This construction wasn't just allowed, but it was given the full cooperation of government. The buildings were either rented (clean legal income from renters), or sold (clean income again).
The only reason this job was figured out was that a government official wasn't paid enough and said something about it. (A rare occurrence.) Think about all of the times it happens unnoticed. By the time the government went after these criminals they had disappeared and were busy working on their next business in another country.
I should say at this time that I do not condone criminal activity. Crime is a social problem that must be understood in order to stop/prevent it.