I understand that there are no users on the Ethereum blockchain and we are trying to beat the transaction speed such that it will be as fast as opening the app on your smart phone. But I am yet to see a wide application of zero-knowledge proof which, although I have seen in Scroll and some other tokens, especially the latest ones aiming to solve security and speed issues, but how well do you think people will cope with this way of making faster and safer transactions?
What do you mean by "common"?
And it's not all about transaction speed or eth scaling. There are different kind of Zero-knowledge proof methods, and more ambitious they are more gas they spend. So this is a balance between scalability and real world use cases. Just sending confidential tokens or coins isn't' costly, but anything that would actually revolutionary isn't going to be cheap.
Like for example the idea of confidential smart contracts, which could technically solve the issue of stolen KYC info. That could also mean decentralized identity, and easy proxy voting, which are some real world use cases that people been hyping blockchain tech being good for.
But there are lots of legal hurdles in the way, and current blockchains weren't really made to accommodate the real world regulations. So using any existing decentralized blockchain tech in voting for example, is near impossible without serious rebuilding it from the scratch.
Like with decentralized digital identities, there are privacy laws , customer- and data protection laws, on which immutability and transparency are probably clashing with. But if we get these solved in some blockchain, it will be an idea worth more money then we can predict.