I got a message from them:
"My name is Tanya and I am a case manager with Airbnb's Trip Experience team. When you sign up for Airbnb and activate your listing, guests will be able to book your space without needing to request approval. This feature can’t be turned off."
Essentially, as soon as you sign up for AirBnB, your apartment is not yours anymore.
By the way, I talked with the staff over the phone twice and they were both really friendly, and they both had to look for a solution helplessly. Anyway, they cannot help you. It's apparently a decision taken from a higher position.
They did not put it into the message, but this feature is for newcomers, although there is no definition for a "newcomer". So it may be one month or two, or five years or ten...