Similar to how "god of the gaps" arguments work, there's a "god of complexity" phenomenon in tech, where people will project infinite possibilities onto technology they don't understand. Blockchain is a brilliant solution to an extremely rare problem. It lets you do distributed consensus among untrusted nodes in a setting where contributing compute power is economically incentivized (e.g. where there's mining). That…
There is a difference between the knowledge of individuals and knowledge of institutions. Many people who seriously looked into these things said it was bogus. But the institutions didn't know it was bogus. They didn't know whether to believe the nay-sayers or not. So "our" (for some weird abstract sense of "our") knowledge increased by doing these doomed experiments.
There was no reason to use blockchain in these cases, except that writing a press release about blockchain would cause a stock price pop.