What does caked-in mean?
> to be covered with a thick, dry layer of something
My mind went to machinery turning rigid and clunky over time due to being caked-in with a crust of thickening dust/rust/tech-debt, especially concentrated on sections "hot-fixed" with the metaphorical duct-tape/glue/lube/almost-fitting-spare.
If you want your machinery running smoothly and be easily servicable with off-the-shelf-parts, you can't skimp on maintenance for too long.