There are simply no offline business models of user generated content, so this comparison doesn't hold at all. Whenever somebody comes up with such a offline business, we will see about it at that point.

> There are simply no offline business models of user generated content

Many newspapers still run classified ads (https://en.wikipedia.org/wiki/Classified_advertising).

Many supermarkets still have boards where people can announce that they have something to sell, are looking for a house cleaner, etc.

And both are subject to acceptance requirements.

There are no offline businesses that show ads? Are you serious?

What about advertisement leaflets and letters to the editor in newspapers?

They just stopped caring when they made the input easier.

Just like websites stopped caring what ads they show.

On nearly every website with ads you can see scam ads

Tell me in which case a place like a restaurant or a movie theater was found to be liable because a consumer suddenly decided to speak harmful speech or violating someone else privacy?...

Not the same.

Show me one place like a restaurant or a movie theater where I can put a poster in their shop window without them asking questions about the content of the poster.