The privatised gain is that a content producer who was previously licensing their content to a streaming service, and starts their own streaming service, makes

The privatised gain is that a content producer who was previously licensing their content to a streaming service, and starts their own streaming service, makes more money streaming than by licensing. The socialised loss is that fragmentation of distribution makes people less likely to pay for any service. By trying to take a bigger slice of the pie, they make the pie smaller.