Not all Playstation Store content can be shared by multiple users, even on the same console. Avatars are one of these. Subscriptions are another. If you buy an avatar, then only your account can use it. If you subscribe to Playstation Plus, some of the benefits, such as online storage, are only available to your account. It was never true that all Playstation Store purchases could be shared by everyone on the same console. It was never intended to work that way.