It is if you're a business. Not so much for individuals. It's the only way I know nostr:npub18s4zkd0wjq5gkthz4paw2704ty4s354wcp2krvxy0sewz3g9z2cs73ydrt is legit without having to contact them directly to ask.
Nip5 is not verification. It’s just a vanity pronounceable and searchable address aka “nostr address” as coined by nostr:npub18ams6ewn5aj2n3wt2qawzglx9mr4nzksxhvrdc4gzrecw7n5tvjqctp424
Discussion
Even then someone could register proton-mail or getproton.co or any other official sounding variant and if you’re not paying attention carefully you could fall for it. Not saying it would be easy or you personally but if you extrapolate this to tens or hundreds of thousands of people; there will be scammed people.
Same can be said for email and phishing websites right?