Good point, but not entirely true. It's not that Germans have to adhere to US law, but that US fines can be outrageously high and German institutions want to keep that risk in check. Insurance premiums are a lot higher if you do business with people from/selling to the US.

> When I'm doing anything with money here in Germany, like creating a bank account, or borrowing money, I have to answer multiple questions about me being a citizen of the USA or not. Why is that? Because everyone adheres to USA law.

Simple: the USA assumes global jurisdiction over anything involving the US dollar and they do not shy away from muscling over US-local branches of foreign companies to get their will.