It’s a package deal in each case, so you’re not really getting the same thing.
When you don’t pay, you get email services, but you sacrifice your privacy.
When you pay, you get email services, and you get to keep your privacy.
Of course, people don’t see equal value in these things. You might not appreciate privacy as much as someone else, and that’s ok. You make your own compromises based on your personal values. We all make compromise at some point.