So I think that you don't need a documentary that explains blockchain. You only need some imagination

I beg to disagree. The blockchain (especially permissioned applications of it) is just a glorified database in some ways. If it were so easy to apply and if it could make everything better, everyone would have already jumped into it. Not every business needs immutability and/or self-verification for their business processes.
You certainly do need a lot of imagination to take advantage of it, but I would argue you would also need even more fundamental knowledge of the technology itself.