Absolutely, I agree that it's a useful pattern. I've personally typed 4111 1111 1111 1111 into a stripe form more times than I want to even think about.

My point above was that it's not necessarily easy to convince the operators of a business that it's a justifiable engineering expense to set up a new "prodlike but with anonymized data" environment from scratch, because it's not a trivial thing to make and maintain.

I do think it's pretty easy to convince operators of a business to adopt the other strategy suggested in a sibling thread: run a dry mode parallel code path, verify its results, and cut over when you have confidence. This shouldn't really be an alternative to a test environment, but they can both achieve similar stuff.