To know if someone is really that account you should check the npub, but that is really long and hard to read.

NIP-05 Verified simplifies that; NIP-05 makes the npub more 'readable'. You can quickly scan if it is really that person. Because the verification is linked to that npub only others cant use it.

It's not the best way tho, and in my opinion more of a cosmetic addition to your profile.

Imposters can always create a domain almost like the one it is using and try to trick you that way.

Example: Admin@N0str-Check.com. Do you see the o is really a zero?