Time-ex
You are correct when you talk about the multitude of other tasks that we carry out, but even running engines (with some operators) on the new generation A/C is a limited and simple task for the avionic trades. They, as you probably know have auto start features which will even auto crank the engine in the event of a hot start. These A/C were designed by the real engineers to relieve the workload on the pilots and the maintenance staff. The Airbus family will spit a bit of paper out on landing and tell you what failures occured, probable causes, in a roundabout way tell you the P/N of the failed item and give you the troubleshooting manual reference. All of these have to be manually done on convential A/C. Remember throttle rigging on the Spey, Tyne and Dart engines? (Could be a bit of a nightmare if you didn't do it often). Nowadays with fadec controlled engines you only need to carry out a leak check post engine change. The whole maintenance industry has been dumbed down by black boxes full of PFM, designed by some very clever people and replaced (only when the A/C tells you to) by you and me. With the advancement of technology, our job is gradually getting much more simple.