Do you think it was equally illegal for publishers and bookstores to sell novels written by Richard Bachman, without revealing that that was actually a pseudonym for Stephen King?
If you can point me to a law that says it's legal to hide a content creator's identity from customers when the content is ink and paper, but illegal when it's distributed over the internet, I'd love to see it.
As others have pointed out, Patreon does exactly this in many different jurisdictions. I find it hard to believe that they're just brazenly violating the law and absolutely nobody cares.
Patreon is effectively the publisher here? Again, they are already doing it which makes your assertion of illegality questionable. What jurisdiction are you, Germany?