I prefer to keep a bit of cash on me for many reasons, and I don't think it's appropriate for any organization to tell me 1. that I can't; and/or 2. that they have the right to know what I'm using it for (or that they have the ability to deny my ability to use my capital in whatever ways I desire).
We're not China. As someone who worked with Chinese nationals, even some of them who were complete simps for The Party had no desire to have all their finances completely digitized and tracked.
Modern economies have a need for cash, no matter what big banks or credit card companies or FinTech companies think.