Even the best known one, Monero, has <1% of the market cap of bitcoin, it's really shameful. Is the reason these coins do so poorly because they are badly designed (which could be everything from the issuance to the mining to the cryptographic protocol to the governance), or is it because no one cares about privacy? Or is it because privacy is difficult to achieve today because of lack of DEX?
Have you seen any store that accept Monero? I still haven't, but I know a lot of stores mainly computer and electronic shops that accept BTC so that is the answer to your question. If world politics starts changing and people suddenly feel the need to hide for god knows what reasons, then you will see rise on demand for privacy coins. But it's unlikely that regular shops that sells TV and washing machines would need to hide their customers privacy.
That kind of coins will be reserved for something else and are probably used even as we speak for kind of stuff where people don't feel comfortable to state their full name or credit card number that can be traced to them.
