I think that situation is echoed everywhere.
In most companies, it is only the older people who know what they are doing or what they are talking about.
But I don't think this is a recent thing. In the 1980s I employed 35 people, and while one could always blame this on incompetent recruitment
it was obvious that the over-40s were taking work much more seriously.
I suppose that in 10-15 years' time the avionics overhaul business will be significantly different, with most of these expensive gyro instruments having been chucked out and replaced by AHRS and "glass" in various forms. But right now these are "bleeding edge" and very expensive options, so it makes sense to overhaul the old stuff for as long as it is economically possible.