Earlier quoted context omitted.
I worry about the same thing. I think "blockchain" (or even just a signed, immutable, public database) is mostly a solution in search of a problem, but I do think it may have an application here. If you can hash a video when it's recorded and publish the hash with a timestamp that can't be forged, you can at least prove that this video existed at least as long ago as that stamp. That allows you to invalidate any deep…
You can have an immutable centralized/federated system without using "crypto" though "proof-of-work", there are databases out there that provide immutable storage that don't require this overhead. Providing api access to a signed immutable database makes sense... but I'm not sure how much sense utilizing existing popular cryptocurrencies would make (e.g. bitcoin, etherium)
You probably don't need proof of work, you're right.