Can a bad ESN be removed from iPhone?

I have an iPhone 7 Plus and it's blacklisted eBay purchase. Is it possible to remove it?

Unlikely

Phone call a phone repair store and ask the employees.

No, the phone is lost/stolen and can never be activated

You can't fix the phone, all you can do is report that you've been sold a disabled phone to eBay and get your money back!

If blacklisted/stolen phones could be fixed like this, the sellers would do it themselves so the phone could be sold for more money.

This is why both new and used phones
should be purchased ONLY from legitimate phone dealers ---
and at that, preferably local brick-and-mortar stores ---
with reputations to uphold.

No, otherwise there would be no point in a permanent electronic identifier.