Tracking tainted coins is already very challenging
Sorry but I always thought of this as a feature of Bitcoin and I will continue to see coin mixing as a non-issue for 99.99% of honest peoples and 99% of dishonest ones.
... Imagine in the future a naive user (your mom, your grandma) who is unaware of the technical details, and keeps receiving and sending Bitcoins always using the same and/or chained addresses. Every time they buy something, no matter how trivial, they are potentially giving a determined snooper/attacker a window into all of their income and purchases since the dawn of time. This is a disaster waiting to happen. It will make life wonderful for criminals in countries (e.g. Latin America) where robbery and kidnapping and extortion are common. ...
Up untill the time Bitcoin is used by most mom-pop of this world it is more likely to be used as a tool facilitating extortion.
You're simply one step further away on that one and we're talking beyond 2024. By then most peoples will most likely be trusting secure 3rd parties for their everyday transactions.
You'd be surprised by how little interest there is in most grandma's banking history.
I wish we could be at the point were we teach them computer security basics but unfortunately it's hard enough explaining them they shouldn't put their life savings under their mattress.