That's a good point; but I don't really believe you need privacy, untraceability or even self-custody if you see cryptocurrencies as just a means of speculation / trading. Because then you're just buying coins to sell them higher later. Traders don't aim to use the coins as anonymous, P2P cash anyway. They only want to maximize fiat holdings and never intend to actually use the currency. So therefore they couldn't care less about anonymity and privacy, right. That's a whole different use case.

That's interesting! Do you have an example? I was under the impression that it's easier to find liquidity of altcoins on centralized exchanges rather than decentralized exchanges (just due to the fact that they have less liquidity in general).