It might be risky to invest in them right now, but privacy coins are not going away. They will likely go mainstream at some point, just as Bitcoin has. After all, privacy coins are just like any other crypto, just with an added layer of security and privacy. For now, though, it pays to keep a close eye on regulatory developments in Washington, D.C. Cryptocurrencies have always been subject to regulatory risk, and that is something that you should particularly keep in mind if you decide to invest in privacy coins.
I agree that it is somehow risky to invest in privacy coins since governments are frowning against them. So better avoid investing in them since we never know when will the government make a full-throttle of privacy coin clean up. We have seen not long ago that the government had already acted on the privacy coins listed on different exchanges forcing these exchanges to delist several privacy coins.