Well, except that there are actually quite a few. Git (distributed version control), for instance. Currencies, for another. Asset trading of any kind. Supply chain management and authenticity validation. Maybe you think those things are 'few', but they are quite critical.
"Few" is quite enough to establish that most people should use something else, regardless of how crucial the rest may be. Speaking of "enough", enough with the "git is a blockchain" thing. It's a chain of blocks, but it's not a "blockchain" in the sense that term is actually used, and everyone knows it. You're not helping your case with that.
Oh, so a thing can have all of the properties of a blockchain, but because it doesn't suit your narrative, it is not one? That doesn't seem like much of an argument to me.
Tell me, which of the conditions of the flow chart does git not satisfy? And better yet, which technical property of a blockchain does git lack that disqualifies it?
You seem to be trying to define blockchain as "a thing without a use case", and then when presented with a use case say "see look it has a use case! it's not a blockchain!".
git is not what people call "blockchain", only half of it. The distributed consensus part is not there. Maybe that's what it's both efficient and popular?
Git absolutely has distributed consensus. That's what merges are. That's the sense in which git is decentralized.
What git does not have is distributed timestamping, which is necessary for a currency, but not version control. And which is why PoW et al were introduced for cryptocurrencies. However, that is not a fundamental property of a blockchain, though it is useful for some (but not all) of the applications of blockchains.
