You can search with nip-05 on nostr.band or on clients like Nostur. It’s useful if an npub has impersonators. Some nip-05 providers offer other services too. Like nostrplebs.com also has a nokyc receive email service
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Nostrplebs also lets you use your nip-05 address as a link to your lnurl address. You can set this up jn the settings of nostrplebs (same for the email service)