Couple of different things I’d like to share:
#1 Re-current training of crews in the simulator
Every 6 months, we get sim checked, some airlines (the better ones) will also throw in a few training sessions before this. However, the training and the sim check ride scenarios are almost identical to the ones before.
We take off, climb to around 10,000ft, get a TCAS RA (traffic avoidance instruction), followed by a hydraulic or electrical problem. We decide to turn back, perform an ILS to land. Simulator is reset, we depart same runway, engine fails upon rotation, we perform a single engine ILS approach with a go around. We come back again to do a non-precision approach to land. Simulator is reset once more, we depart, there's an engine fire prior to rotation, we stop on the runway, carry out the evacuation. The sim session ends and we go home.
In 5 years of flying the Airbus, my training / sim check scenarios have not deviated from the above. In fact, I've never climbed above 15,000ft in a simulator ever. I've never had an unreliable speed problem (other than a single ADR failure which results in one of the PFDs spitting out an inaccurate air speed - no big deal, switch the source over to ADR3) and even that was in simulated visual conditions.
There is so much that could potentially go wrong in flight, most of the training focusses on resolving issues related to that specific aircraft. The handling, unusual attitude, and partial panel (where only some instruments are available) skills you learn during initial IR training do not get practiced in a medium/large jet simulator. It is assumed what you learned on a single engine piston plane will stay with you forever. Quite simply, training budgets don’t allow for this kind of training and it's my personal belief that airlines will probably end up firing many pilots who are simply not up to the job. Yes, I’m sad to say, but within this industry we have a very large pool of semi-talented people (especially in the third world) who are only in paid flying jobs because of nepotism and friendly/financial/political favours.
#2 – Software/hardware improvements and bureaucracy
There are countless improvements we could make to modern EFIS setups that would help enormously and it's no secret that the avionics of many modern general aviation aircraft are far better in terms of features and functionality than what Airbus and Boeing are producing even today. Despite, the industry experiencing some pretty disastrous events; we have not seen much done. After learning lessons from accidents, and to avoid the likelihood of repeats, a few software changes are all that is required to decrease the likelihood of the same mishandling to occur. The inputs are there because they are integral to the original design of the aircraft and in most cases the computing hardware is there too, but the logic wasn't considered at the time of initial design. However, even minor software changes need to go through exhaustive certification processes that end up becoming uneconomical for manufacturers to pursue. Thus, we typically do not see improvements for 15-20 years.
I have perhaps not made this point properly but I have also worked in other industries where the timescales associated with idea inception, coding, testing and certification are much smaller and the costs highly manageable. In aviation, the progress of change/improvement is heavily stagnated.