if you need accurate verification, or it boils down to a single person, agreed. (though that's not often possible, e.g. bribery)

if you need to know the final consensus (or lack thereof) about that verification, regardless of how consensus is determined, it's not a deal-breaker. multi-party signatures, basically, which is what ethereum is designed to do.

(for context tho: broadly I agree, blockchains make zero sense in very nearly all potential scenarios)