> "well what specific laws would I write to combat addictive design?"

Expand the GDPR "Right to data portability" to publicly published content for third parties, i.e. open up the protocols so you can have third party clients that themselves can decide how they want to present the data. And add a realtime requirement, since at the moment companies still circumvent the original rule with a "only once every 30 days" limit.

Also add an <advertisment> HTML tag and HTTP header and force companies to declare all their ads in a proper machine readable way.

The core problem with addictive design isn't the addictive design itself, but that it's often the only way to even access the data. And when it comes to communication services that benefit from network effects, that should simply not be allowed.