Some of the technologies you describe here have a problem: they don't really need a blockchain or are itself only useful to speculate.

One example is DeFi. There are only very few DeFi protocols which really solve a real need. Most DeFi protocol instead enable you to speculate with one token, depositing another token as collateral. As simple as this looks, most DeFi apps are variations of this concept, some of them quite complex as they use long "chains" of different tokens. The only DeFi use case I saw which solves a real-world problem are algorithmic stablecoins like Dai.

Web3 is similar. Most tools of this "space" could be realized as centralized platforms as well, because the project emitting Web3 tokens is a centralized entity in 99% of the cases. The same goes for tokenized assets: they mostly have an issuer, which could also use a traditional (non-blockchain) exchange to issue it.

Privacy tools is the only technology of your list where I really see an advantage for blockchain based solutions. Censorship resistance is one of the most unique features of crypto, and privacy is directly related to it (you only can't be censored if you're private).

ICOs however could be useful as an alternative to loans for companies. However they are so deeply associated with scams that they currently don't live up to their potential and I don't know if this can change in the short term.

Thus I'm quite skeptical about most altcoins, above all about those who do not really solve the problem they promise to solve.