My concern about these deletion request is that you are totally at the will of the platforms, that they actually will delete your data. This already imply trust towards them. And if you have trust they handling data with responsibility, why would you need to ask for delete?
As someone who supported a major database in Google some five years ago: the amount of development effort that went into the GDPR compliance (we haven't even heard that name then, only that the EU is brewing a law that requires us to be able to delete data) was very surprising. So at least one corp does actually delete the data correctly.