lol
Of course they don't go unnoticed, far from that. But the central banks and world's largest banks know how to keep their mouth shut, so do the governments they control.
No inquiry from your side (or any other citizen) will ever make them talk. These people don't talk in public about these matters. They never do.

Ask yourself just who owns the world's central banks - then you're getting closer... Then realize a few Trillion Dollars literally don't mean shit to these people, they can print them at will in almost any currency they want - almost worldwide.
They're not interested in paper FIAT other than in its function as a control tool to them. That is what I'm talking about...