The fundamental problem is that PPL pilot training syllabuses were designed in the 1950's and adapted from WW2 military training. This is not inherently bad in that the foundation hands and feet skills are still as applicable as ever, however what is missing is a system for effectively using modern cockpit technology. This is much more than buttonolgy it is an inflight decision cycle aided by technology. This has to start with defining what information a pilot wants for each stage of a flight and is equipment agnostic. A critical element is understanding when and how to step down the technology level (eg declutter the screen) when the technology is working against the pilot not for them. Finally instruction has to embed a rolling gross error check into every interaction with the technology ( I used the term TLAR, That Looks About Right)
For example. When I ask the PPL how he is going to program his GPS for a trip I usually hear "Direct to" or "I will put these waypoints in the flight plan page". What I would suggest he should say is that after referencing weather, airspace, terrain, and aircraft performance my lateral and track will be this. To get that, the lateral track should look something like this. I will then decide on altitudes based on wind and terrain and then enter the appropriate waypoints into my navigator. Finally I will do a TLAR check for each leg. Instead of going straight to the how I am starting in an organized way with the what and the why, before getting to the how.
With respect to autopilots I am a FMA (Flight Mode Annunciator) doctrinarian with my students. That is every change of mode MUST BE verified with the appropriate annunciation. I also insist that climbs are only done in IAS or FLC mode and descents are only done in vs or vnav mode.