I see many people treat regex as an in-app library and argue about that. But in fact it is a text processing tool. It is not important if you're biomed-dev with a honorable degree or web-dev from 'secondary school'. What is important is how you manage your code and constant data, which is mostly text that doesn't care who you are. How do you manage your code? What do you do if you understand that you need a module extraction? Documentation fixes? Managing any text includes non-trivial search and replace or specific tools, right? Either you know one of these, or you leave your mess as is. If former, you have to know something anyway. If latter, well... not much honor.

I agree. If I ever need to use regex, I will dive in, but I don't mainly write software to process text. I mainly write control software for various things like subsea oil wells, oil rigs, gas turbines etc. It is enough for me to know it exists. I try to spread myself thin and broad, and then that gives me the control of which areas to dive deep, depending on the task at hand.

Well, maybe I think that the ability to use the search and replace function in a text editor is a foundational skill. Maybe you're a better programmer? I know programmers who don't even need to write code, but I wouldn't think they were good programmers.