Nobody learns anything from a finished job
Half of what I did on a job was teaching. Not classes, nothing formal. You show somebody where the switch is and make the person do it once while you watch. You write the note for somebody tired and in a hurry, and stick it where the machinery is.
The point of it was simple. A job that left somebody no better off than I found the place would be back within the year, worse, with no time to do it properly.
The measure of a job was never the thing I built. It was whether the person needed me less the next time, and the best sign was a question answered before I was rung.
That half has thinned out, and not because I stopped bothering. The work comes back finished. I describe the problem, the thing arrives built and working, and it is better than what I would have done in the time. What it does not do is leave the person any better at the machine in the corner. There is no explanation in it that somebody can keep. Nothing in it is small enough to hold.
From the outside this makes no difference. The job gets done either way, and done well. What has gone is the part where a person picks up a switch, a command, or the place to look when the noise starts. It was never on a bill and it was the part that outlived the work.
What I do about it is slow and it is not asked for. On every job I find one thing worth teaching, one switch or one command or one place to look, and I have the person do it in front of me instead of describing it. Then the note, in the words the person actually uses rather than mine, left by the machine. It takes a few minutes I am no longer paid for.
Half the time I think it is wasted. The person nods, writes nothing down, and rings me the next time something goes wrong. I do it anyway. Being shown a thing badly and keeping a bit of it is better than a finished job that leaves the place exactly as clever as it found it.
I am not going to pretend the work is worse for the person paying. It is faster and it usually works. The job used to be two things at once, the fix and the teaching, and only one comes back finished now. I still do the teaching, wanted or not, because it is the slow half and it is the half I would keep.