I really hate that the exaggerated future of Watchdogs is becoming reality but not the exaggerated group of highly experienced black hat hackers doing crazy post compromise shenanigans that would make national news.

The problem is the same reason why a Robin Hood type of character already doesn't really exist in modern history. There will always be thousands of highly skilled people in defense of the very system you wish to see dissolved.

You would need the resources of at least a highly advanced APT, which often means you're funded by a nation state which has very specific compromise goals.

Everyone else falls into cybercrime, which is much less sophisticated and is almost always after money.

Hence why most highly publicized attacks end in bitcoin ransoms.

EDIT:

Also at the risk of giving too much info about my career, big banks are absolutely notorious for having extremely tight security. Even if you managed to jump over the custom EDR, pivot your way through a massive amount of proprietary systems, and land in a suitable position to carry out the motherload of a supply chain attack, the bank could just halt their infrastructure and manually nullify whatever transactions they want with full backing from the government.

The closest I ever hypothetically witnessed was being able to manipulate the loan data for a small credit union. And emphasis on hypothetical, a real attacker would have needed some hard internal access to a heavily restricted subnet.

The only way I can see this successfully happening is like if the Chief Network Architect of say Chase also happened to be a highly competent hacker who uses his decades of experience to formulate a plan with an APT over the course of several years.