This. I noticed that I have gone for over fifteen years through some pretty tough jobs, but never needed to write any Leetcode binary tree problem from scratch in thirty minutes in my work while being questioned. I normally freeze up because I worry about current best practices every step of the way.

In the end, I scored a job with a FAANG company literally because I didn't want to work there. A friend warned me away before the interview for work-life reasons, but I decided to go ahead with the interview anyway as practice and I nailed it. There's no reason to stress if you don't want the job. Another friend who worked there later convinced me to take the offer.

What bothers me is: you're basically the same coder both before and after competitive coding practice. You're only more marketable with the same skills.