What would 'being smart' about using these services mean? It is pretty difficult to get through life in the modern age without using email for sensitive documents (or at least without using ACCESS to your email as a way to gain access to sensitive services, eg password reset emails, proof of ownership, etc)
Since email in the modern world has this type of importance, what should I do? If you say gmail can't protect their data forever, do I not use gmail for email? What do I use then? No service will be free from data leakage, even an email server I run myself.