NIP05 does NOT prove identity, if MOST (or any FTM) users are simply buying them from vendors. It validates nothing.
NIP05 only asserts the uniqueness of an arbitrary human readable username. Nothing more.
NIP-05 is an easy way to provide a proof as to your identity. It does not prove that the identity is trustworthy.
Generic NIP-05s are fairly worthless since you’re not in control of it. If you use a domain you own, for the NIP-05 nostr:npub155m2k8ml8sqn8w4dhh689vdv0t2twa8dgvkpnzfggxf4wfughjsq2cdcvg supports this) it will add a lot more credibility (but will doxx you).
Discussion
You can prove owning a domain, thus prove *an identity*. That’s what I meant. But you’re correct - it does not prove who you are.