As another German, I think there is different kinds of corruption. There is low-level and high-level.

Low-level is when you bribe individual cops, city clerks, etc so they let you go instead of writing a speeding ticket or approving your house building plan.

High-level is when people like Merz receive a political donation from McDonalds, do some self-promotion in one, and then keep/lower the Mwst (VAT) for restaurants.

Germany unfortunately has high-level corruption but as far as I know, very little low-level. I think thats partially why people don't care to vote to differently. Yes, it happens, but there is a large disconnect between what Merz does and how it impacts an individuals bottom line.

If people would have to constantly hand out bribes to anyone then maybe its a different story.