Oh that new building code or electrical code just so happens to only be fulfilled by using the latest (patented) product by company X?
Well it's the state of the art, we can't build below that standard anymore.
EDIT: Nobody wants to donate overtly to the AfD, that's why they had already multiple investigations into their finances and donations. A large part of which came from Switzerland. They do have those donation scandals in common with the CDU and CSU, those received anonymous donations in cash in briefcases. And Schäuble, who ended up as Finance Minister in the federal government later, got away with, I kid you not, "I do not remember that briefcase containing 100,000 bucks" (emphasize from me). So, it seems all parties in Germany are corrupt, some more than others, with the exact degree of corruption directly proportional to the time in actual power.
This is true in most highly industrialised countries. Can you name any where this is not true? I don't know any.
Another way to think about it: What is the polar opposite? "the large companies ... extremely unhealthy / combative relationship with almost all [political] parties". That sounds like the bad old days in 1980s India. Most economies would be a wreck if that were true.
But at the large scale, we are absolutely a corrupt nation: our former Chancellor Schröder sold us out to Russia, there have been dozens of millions euros worth of (shockingly ruled legal) corruption during the pandemic, the large companies ("Deutschland AG") have an extremely cozy relationship with almost all parties in Germany, not to mention corporate donations and sponsorship of party gatherings (except far-right AfD whom no one serious wants to donate money to and far-left Linke who refuse to take corporate donations out of principle).