To access the DB through the modern archive (well modern as new rules) you'd have to be an accredited professional passing through a few legal hardles and digital chancellor's office for each copy. It's like going to a bureaucracy^bureaucracy office.
Some early companies given their initial foothold were not required these checks so they were able to get hold of bigger archives (it's also important to remember often legislation or conformity is done through consulting or lobbying done by these entrenched players).
They can also build on the Data professionals themselves submit.
