Multiple Leads with the same Email

Why we can not enter more than a lead coming from the same email id ??
always get a message :
Email id must be unique, already exists for LEAD-xxxxx


This is the validation message. ERPNext allows you to manage email communication with client from the Lead itself, hence validation on email id.

You can create multiple Opportunity against one Lead, and assign those Opportunities to relevant Sales Person.

Can I merge two leads with the same email ID? Or two leads with the same phone number?

Is creating multiple opportunity out of the same lead, the only way to handle duplicates? Merging would have been a good.