I was an aviation electronics technician in the Navy, and I can say from experience that it is very easy to underestimate the time and effort that can go into a component-level repair job.

I once troubleshot a faulty RF power meter down to a single transistor, and it was incredibly gratifying to see it working after replacing a sub-$1 part but if I was paid by the hour it would’ve been an unprofitable job for sure.