The biggest problem is that no matter what “scale” of tracking is tolerable on a single domain / subdomain, Facebook still gets the aggregate. So if you fix it

The biggest problem is that no matter what “scale” of tracking is tolerable on a single domain / subdomain, Facebook still gets the aggregate. So if you fix it for small multi-tenant domains, nothing changes for Facebook and they still get all the aggregate data, right? There’s going to be a lot of collateral damage before ads and tracking get fixed IMO.