I've actually gotten into trouble because I spent more than 5 minutes doing a code review of a pull request. I had to code review for 3 junior devs and one senior; the junior devs all knew little Python so only I could review their code while the other senior dev was busy. It took hours to wade through and double-check their code. I always suggested to them to look up some Python libraries or to work on puzzles to practice or to review the code as well or talk to each other about the next piece of work. There's so many other things to do than to keep coding.
That sounds less like "code review", and more like "Mentoring". If you find a way to position it that way, you can bring that up with your boss(es) before your next performance review.
I've found mentoring other developers (whether it's explaining "Here's the facets of how we test All The Things", or "Here's how git branching works") to be profoundly fulfilling. I love explaining things. The best part is, fostering the idea of teaching each other means that others can mentor YOU as well on things, and you (and they) don't need to feel threatened.
