But from that, there is no way you should conclude that cynicism is wrong in general. You should not overreact to too much cynicism by discarding criticism entirely! You should react by seeking better information.
I haven't personally looked into blockchain or related ideas enough to get excited (I'm harder to excite now that I'm older, and I have less time) but sometimes I feel like I ought to, just because the flavor of the criticism reminds me of the smug nastiness that got directed towards people who were interested in things like computers and Star Trek when I was young. These nerds think they're onto something cool, and we have to mock them until they can't believe in it anymore. I almost feel like I should start learning the technology out of solidarity with the little kid I used to be who embraced computers despite knowing how hopelessly dorky that made him.
Of course the concept of nerdiness has been socially rehabilitated since the 1980s, and now the stigma is nominally directed towards scams and environmental waste, but the people delivering the stigma have designed the blast radius to work pretty much the same. The entire topic is stigmatized, any interest or optimism is stigmatized. I think the history of computing and the internet shows that it's hopeless to try to disentangle the utopian hope for social transformation from the grifting and greed. Scam artists can smell the hope for progress and transformation like sharks can smell blood; it means a meal for them. It's a crude distortion to argue that either optimism or greed alone properly characterizes "web3" without the other. When we look back twenty years from now they'll both be part of the story, whether these ideas fizzle out or have a transformative impact or something in between.
> And a whole bunch of problems who we don't even realize exist that can one day be solved
A few keywords: threshold signatures, zk-snarks, consensusless protocols, byzantine fault tolerant protocols, vrf, vdf, starks, bls