As a mid-career software dev I'm just sick of most of my job being a highly paid technical janitor mopping a floor that never gets clean.

I've had maybe 2-3 years combined where I actually got to build something I could be proud of, and made all the red tape worth it. The rest has been navigating/paying down other peoples' technical debt and being forced to add some of my own when there's no budget for maintenance and the band-aid becomes permanent.

At the start of my career I wondered why anyone retired early when there was so much cool stuff to work on... now I get it. The cool stuff is the extreme minority of available work, and the odds of you getting to work on any of it are down to being in the right place at the right time. As for the rest of the job, I'd sooner step on a nail if it didn't come with the pay and benefits.

never seen a better description than your janitor metaphor

the term your looking for is "worker alienation"