I agree, that the EU breaking up the tech giants is insane, but I don't think that banning them is much better. How would you enforce this? I don't want a big firewall like china has.

I'd argue for open protocols that allow exporting your data and switching services instead. Make export capabilities a requirement akin to data protection laws, and you have defanged the monopolistic nature of tech. Ideally also force interoperability between services, but that's a whole other can of worms.

This is on paper obviously much harder than just banning something, because you would have to define such exchange protocols, but it has a chance of success. One could start with certain industries, like social media, and in some cases build on existing work, like the AT or ActivityPub protocols.