Right. When "Enterprise" says "blockchain", what they mean is some combination of cryptography, an immutable database, and data/control/access/ownership flow logging. Sometimes also a financial product.

I think this word is now like "hacker" or "AI". It's not completely meaningless -- it does have a kinda-sorta fuzzy meaning. But that meaning is different from what techincal experts mean when using the term and is very much audience dependent.

That's just misusing the word blockchain. Like saying "cloud server" for "hosting" when there is nothing cloud about it.

Using digital signatures in a chain is not a novel idea. Without PoW you do not need the block part, just records.