Not crazy, it is just convenient. Constant pushes with Android, Chrome, random websites asking for Google login.
Google wasn't always like this, and moving of from an email address isn't technically hard, but something that 99% of the people will be very very reluctant to do.
Ex googler here. It is based on Google’s fundamental disdain of customers. Googlers are repeatedly told by management that they are the smartest people in the world and that their time is too valuable to spend on silly things like helping customers.
Google has zero customer service. using them for anything serious makes no business sense. the only thing that they're good for is serving ads to people, and they have a support team for that, but only if you're spending a lot of money, and even then good luck finding it