Jyoti, 
If email was invented now, it'd be something like:
WeMail™ by Meta
and be totally walled. You're either on it or not and if you're not, no email addy for you! You just have zero email service.
IRL, people understand that you can have email provided by Gmail or Microsoft or Apple. Many servers! That doesn't hurt their brains.
The fact that so many think Mast is "complicated" is not because they're stupid but because walled-gardens have ruled for the last 15+ years.
Time to change that.
