Yea a normal person isn’t hoping on these p2p platforms. I can because I’m deep in the space. If I asked me friend to do this on my behalf he would laugh in my face. Yea the key point here is no-KYC at point of sale. Not forward privacy with coinjoins
You're never going to be satisfied with the answers you get here because there simply are not cookie cutter granma-friendly procedure.
And the reason for that is simple: the government rushes to put hurdles in your way as soon as a good solution comes up. This is not something that can be solved with tech alone and it will always be hard to keep your privacy.
Another way of looking at it is that you're trying to find a seamless and private interface between decentralized perfect money (Bitcoin) and the legacy financial system, which is centralized and inefficient by design. You simply cannot square a circle.