No, there isn't. It is all competition. The level for extortion is pretty high. There are US style CC offers for unsecured loans with 16 APR on the market, however, this is only a niche business.

Germany is not a "debt culture". My parents would have never taken a consumer loan. One gets his/her your money together and only then spends it. Todays generation is not so much different. If I need a loan, I take a loan from my bank, no wild spending on CC. I personally never ever bought a car I did not pay cash and the only debt I have is for my house and secured by my house. This is hell for US style CC operations and they have certainly no incentive or business model for granting a big sign up bonus.