Thank you @jmcgirk.
Privacy coins are a great alternative for people who take their transaction privacy very seriously. However, as you rightly pointed out, it is yet to take off as a replacement for Bitcoin and other cryptocurrencies. This is due to a number of reasons, first, privacy coins are private to a great extent but they are not impossible to penetrate, emphasizing the fact that the theoretical guarantee of privacy is different from its practical guarantee.
Also, privacy coins are often under serious scrutiny by governments and people because of their money laundering and terrorism funding use cases. Importantly, they attract higher transaction fees therefore it is just easier for individuals to go for cryptocurrencies with lesser fees. I believe these are some of the reasons the use of privacy coins is not as widespread as other cryptocurrencies like Bitcoin and Ethereum.
Conversely, one of the arguments against public blockchains is that it does not comply with data protection laws in terms of the rights granted to individuals. The use of privacy coins could bridge the data protection gaps in public blockchains by allowing individuals to transact anonymously and potentially untraceable.
Therefore, when it comes to regulations, governments have to weigh the potential use of privacy coins to promote illegal activities with their potential protection of people’s privacy rights. A dicey situation I must say.