It's one of the best uses of your time. No one is going to notice your papercut bugfixes. There's a good chance that the bug-fix itself will be deleted in a few months with the rest of the code.

However, a written artifact of your technical thinking and contributions with your name on it will outlast probably even the company.

These things matter. Unfortunately there's so much garbage self-promotion nowadays through Linkedin and other platforms that the pendulum has swung in the other direction for people with actual skills and expertise.