I agree that this would be great, but this is not a new idea, people have been talking about these things since 2008-ish. Unless you have a firm proposal, I thi

I agree that this would be great, but this is not a new idea, people have been talking about these things since 2008-ish. Unless you have a firm proposal, I think we're at exactly the same place as we've always been: everyone agrees that it'd be nice, but noone has any idea how to make it happen[0]. The useful work also has to happen as a byproduct of the blockchain securing calculations, because if it's seperate, the blockchain will offer worse security properties than a competing blockchain with similar hashing power, so there's a disincentive to use it. [0] There was PrimeCoin, which computed some series purported to be mathematically interesting. Math people I've talked to mostly shrugged their shoulders when I asked them whether that work had any real applications.