There are alternatives for people who prefer to keep their privacy intact. The use of Bitcoin mixers is not the only way for a user to stay private. Having said this I think we really don't need Bitcoin mixers. We need ways to provide us privacy but Bitcoin mixers don't have the monopoly of this kind of service. The example given in the OP also provides privacy. CoinJoin also provides privacy in a manner that is legally acceptable. During these times when mixers are perceived negatively, there remains other ways to achieve what one can achieve with mixers.
Between mixers and airgapping a perfectly usable device to act as you wallet, mixing your cryptocurrencies is definitely going to be the more appealing option.
You have to consider the fact that the reason why mixing is so prevalent even after getting some leering eyes from the international global scene, is because it's the most convenient way out there to secure your cryptocurrencies, and to protect your identity. Sure, converting your bitcoins/crypto to monero's an equally appealing ordeal but the concept is not explored to its fullest capacity just yet, forcing people into instead following what the norm is, which is mixing. Airgapping and other forms of cryptocurrency anonymity tactics are cumbersome as well in the face of completely obscuring your footsteps with the single press of a button. Which is why at the end of the day, mixing will remain existent even though we don't technically need them anymore.