Thank you guys so much for your inputs and for sharing your experiences.
I completely understand both sides here - yes, many of my colleagues are out-of-shape and outdated skill-wise, but I have several really great colleagues as well, which I work a lot together with. I work at a medical research library, so I do mostly one-on-one lessons with phd-students and in-house researchers who need help with academic writing, systematic searching for recent academic articles etc., so the job itself is (at least for the time being) pretty challenging. The reason I said it was an "easy gig" was because it's totally up to me how much work I want to put in - if I wanted to be a lousy worker, I could just say "yeah, here's Google Scholar, do it yourself!" and get back to checking Facebook, as you won't get fired as a poor government worker. Which is truly a shame IMO. However, I actually find it rewarding to help out researchers in the best way I can as they really appreciate my help. (When people ask me what I do I usually say that I am, in a very - very - very indirect way, curing cancer and saving the world :D)
The reason why I started this thread was primarily to discuss salary progression and whether I should look into other jobs to get a higher annual salary. Like I said, I pursue music on the side and find a LOT of challenges when composing, recording and performing, so I personally don't have a big need for a "perfect" day-job.
I do understand that some people will not understand this choice though, as many people look at their day-job as their one and only passion, and I'm perfectly cool with that. For me, music and language learning are my biggest passions and when I get to work on those I do my best work. However, I came to realize that I cannot easily make a living playing drums and speaking foreign languages, so that's why I need a day-job until I FIRE :)