Pay or have ads is fine by the EU’s DMA law too. What isn’t fine is the collection of user data without consent. Facebook can show all the ads they want, but if they collect user data to target those ads they need consent.
Think about radio or TV advertising - those aren’t targeted at specific people, but rather they’re targeted based on what channel, time of day and TV shows that they’re around. Meta can do the same stuff, but they just don’t want to give up that lucrative user data.