An interesting problem, not something I'd lay at the feet of any number of neglected or underrated jobs - though one could see the poor delivery of the system / service as a whole where those people were employed, is more often at fault.
Foremost as an example of this, from my pov that my region, similar to various regions around the world, is the few decade decline in educational services be it academic or trade. It's not the educators themselves, it's the system, the working budget and prices now charged / demanded. With the digital era, books, notes and other materials should be practically nothing since with enough people within that educational field, they can practically write their own material required. Disappointingly it has not, more often more money spent, to the benefit of the commercial sector.
In my locale, IMO many of the educational problems begin early in childhood. The education system has been slowly bent to be more inclusive and mindful of underachievers while seems like a good idea, stifles those who might not otherwise not yet have the capacity to seek out further material relevant to the taught subject. Later education from my short experience of it, misses the aim to teach and educate and focuses instead on memorising and passing exams. The onus I guess is people pass they should know some or most of it, but too often I've run into people who should, but haven't a clue.
Preserving hard won insight and information necessary of former systems though might be something a project can address. I've not doubt to do so would be complicated to sort out myths from working knowledge. Perhaps a better sort of wiki that deals with process, maintenance and troubleshooting, possibly with who still supplies various hard to get parts.
[I felt that was what one of wikipedia's (originally) aim was, many people in the first couple of years of wikipedia's arrival, moved precious information to wikipedia and let their own hosted page go. I don't know how many of us spent hours (tens, hundreds) posting up rare insight, trouble shooting tips they'd come upon their own or was gifted from former long term personnel in that particular field of work. Wikipedia from what I understood, a few years in, deleted much before archiving an awful lot of that sort of content because it took up too much space, wasn't relevant ... but from the present attitude there, it wasn't verifiable.]
At the end of this, I would say I can't see a solution that a single person can work out, or take a pay cut to solve. If any number of easy solutions were radical to address the how, what we needed to continue to enjoy a life as we know it, if that solution infringed on only a few dollars of a multimillion company's profits, it would not find favour publicly or govt levels (there would be an underhanded PR campaign) and thus ... humanity already relies too heavily on keeping a small percentage of people appeased.