Agreed, there are use cases, even obvious use cases. Blockchain provides guarantees that other databases do not. They're just guarantees that assume that some portion of people connecting to it are bad actors. Most people don't really care about solving that problem because they just don't give those people access, but that implies a single authority for access ie: centralization.

So blockchain only makes sense when:

a) You have bad actors

b) You need decentralization

The use cases for that are, for the most part, "subvert government authority". There are some cool other things you can do, like web of trust stuff, but the vast majority of the market is in the "subvert government authority" in one way or another, or is an outright scam.