Crypto currencies are the only part of blockchain/crypto/web3 that's actually not a scam. They do work if you treat them as a means of transmitting money, although they do make many trade-offs to be trustless, private and censorship resistant which means that in practice they are an inferior alternative to fiat currencies & traditional finance if you have the option to use those, so the only legitimate use that remains is either grey area/unlawful transactions or legal transactions in locations where traditional payment rails do not exist or are outdated.
The problem is all the "utility" tokens and other bullshit in the crypto/web3 space. None of that is required to operate a legitimate business in the real world, should there be an actual, sustainable business behind it. But the truth is that there's no business and the whole crypto/blockchain/web3 concept is used as a smokescreen to conceal that fact and be able to make off with the gains of the underlying Ponzi or pump & dump.