Wall Street and banks are rolling out Blockchain based systems because they are finding efficiencies in their niche. Cryptos are good for settlements, beyond that, I am typically a big critic like most of HN. But let's be realistic here, there are some niche use cases, especially in finance, and Blockchains are not completely useless

If you look ahead to GovCoins and stable coins, there will be crypto in most parts of your life. Do you really care what database and settlement tech your bank uses? (assuming you UX is essentially the same i.e. custodial wallets so you don't have to deal with keys)

Also consider it took linux more than 10 years before adoption really took off. Why should we expect a novel system like blockchain have a more rapid adoption rate than something as ubiquitous as linux?