Even more so, when you're interviewing somewhere else you (and usually they) want to talk about new things you deployed or new systems you created, not how you maintained this boring code base for 2 years.

it’s hard explaining and assessing work done in maintenance. interviews are also really stressful.

I've had good results highlighting performance and security-holes I've fixed.

Engineers also sympathize/appreciate with improvements I've done just for my own sanity, like making the build pipeline faster.

None of these where things I did because someone told me to, they where things I do because I cared. Meanwhile plenty of my peers ignored the problems or couldn't be bothered to fix them.