> if some new chinese website becomes globally popular, the EU will try to prevent its business from paying money or buying ads from such company?
This is a red herring. The hypothetical involved Facebook, a company serving European users and with equipment and people in Europe, reacting to European regulation by moving said equipment and people out of Europe while continuing to serve the same Europeans. That is skipping jurisdiction. Given such a blatant attempt to skip the law, while still doing what the law was designed to prevent, one expects enforcement.
A comparable hypothetical would be an American company reacting to an American law by moving its people and servers to Canada while keeping all its American users and then saying "we're no longer in America, you can't touch us."
This is a red herring. The hypothetical involved Facebook, a company serving European users and with equipment and people in Europe, reacting to European regulation by moving said equipment and people out of Europe while continuing to serve the same Europeans. That is skipping jurisdiction. Given such a blatant attempt to skip the law, while still doing what the law was designed to prevent, one expects enforcement.
A comparable hypothetical would be an American company reacting to an American law by moving its people and servers to Canada while keeping all its American users and then saying "we're no longer in America, you can't touch us."