We shouldn't value net-negative tinkering, which is what pyramids and pump-and dumps are, so I would say that these engineers are mostly making the world a worse place.
However, I don't think most of the work that goes into internet companies at the moment necessarily makes the world a better place, either.
and this gets at what's really threatening about web3: it's an inherently libertarian technology and authoritarians on both the left and right of the cultural/political spectrum are terrified by that.
It's libertarian in the sense that the final stage of libertarianism is that the well-connected insiders get to abuse everyone else, with zero recourse against them.
In this sense, Web3 is a tremendous success of libertarian thought. No rules, no laws, and an absolute honeypot for hustlers, thieves, and fraudsters. Anonymous founders running off with the money, repeat fraudsters pulling off bigger and bigger heists, and money being poured into the dumbest schemes which, inevitably, end poorly.
I can't think of a better condemnation of libertarianism.
This authoritarian approach justified "for the good of humanity" is dangerous. It actually makes me sad this comment is on "Hacker News". We should value tinkering and hacking on what we enjoy.