We had permissionless distributed databases (that's all blockchain is) in the 70s. They failed because they are hugely inefficient and extremely resource intensive with each added node.

What's old is new again. I'm old enough to have used one of these in the early 80s, learned about from a BBS I was frequenting.

I suppose that referred to Merkle trees? Those are from 1979.

I guess. "Merkle trees are a miserable hunk of garbage" seems like a slightly extreme view to me.