Most of the negative comments on this thread read like knee-jerk reactions. I'd wager that many of them see blockchain as Bitcoin, and they are not cognisant of newer developments like zero knowledge proofs, verifiable computation, and smart contracts running on a zk rollup.
Zero knowledge proofs have nothing to do with blockchain, verifiable computation has nothing to do with blockchain.
You can use Zero Knowledge proof with many things, one of them is blockchain.
This inverses the relation of Zero knowledge proof and Blockchain, Its like saying supply chains are an advancement of blockchain. Just because you can do something (poorly) with blockchain does not make it part of blockchain.
This kind of inversion of relations stands in the base of why people with subject matter knowledge are opposing Blockchains/Crypto. Its a tower of badly constructed arguments standing on top of each other.
Private money is not a blockchain advancement, Supply chain management is not a blockchain advancement, Consensus algorithms are not a blockchain advancement... and zero knowledge proofs are not blockchain advancement.
Each and every one of this things can be done better not using blockchain.
ZK is old tech but succinct, non-interactive and general purpose ZK is not. Look at SNARK and STARK, and every other research and advancement in the last 5 years. Funded by blockchain, developed for blockchain, with hash functions optimized for use in a blockchain. This modern form of ZK underpins most new blockchain bridges, light clients, and scalability solutions.
These new ZK proofs are much different than anything in the last decades, and can be used without a blockchain. But they also do fit elegantly within the context of blockchains, like having a ZKP verifier running on EVM instead of a single website like keybase.io, to further reduce points of centralization.
"ZK is old tech but succinct, non-interactive and general purpose ZK is not." Do you work on SNARK? this is just their marketing language reiterated.
Zero knowledge proofs do not need to be "small". What kind of ZKP use-case do imagine that cannot bother to send 1kb of additional data? What does any of this have to do with decentralization? Why is decentralization a goal? Do you really believe that most research into ZK cryptography is funded by blockchain?
Try and expand your sources of information, I have a feeling that you are in an internet bubble :(
Succinctness means the proof size is smaller than the witness, and that it can be verified quickly. So your proof size and verification time can remain small even with large inputs. Succinctness and SNARK is the basis for practical verifiable computation systems like Pinocchio[1], early applications like Zerocoin, and now is the basis for scaling blockchains with ZK rollups.
See for yourself[2]. Much of the recent developments of practical ZKP stems from SNARK. In the last few years there has been an explosion of new papers and tools around this - lots of it driven by blockchain and in some cases directly funded by it.
Zero knowledge proofs were first invented/described in the 90's. Verifiable computation is older than blockchains and zero-knowledge proofs. Neither of these have anything to do with blockchains.