Interesting, I actually built off Mycelium's Swish platform that sought to do this very thing. We built an Online eCommerce platform with B2B, and B2C to generate fees for them with BTC enabled payments. But what you described is exactly the way it was pitched [0], it just never got any traction and was not really use for most people as it had limited usecases.

0: https://www.youtube.com/watch?v=xVIeLfuSUJo