I abstractly agree with you. There is a level of obscurity and disposability that should be tolerated in these accounts. They’re just a row in a database somewhere anyways.
That said, many people transact with these businesses with real human money. For example, YouTube premium subscribers or content creators. From a practical perspective, that requires IRL identifiers to be stored somewhere with that otherwise disposable account. And due to fraud risks and other realities of banking, that requires giving these businesses actual identities and addresses which they store too.
While I don’t give random apps and websites my human-identifying information, anyone I do business with necessarily knows the real me, which is a theoretical point of data leaking.