Training is good, and necessary of course. Not everyone will respond the same way; some will really try to understand the training and store it in their brain as well as be able to pull that knowledge out when required. unfortunately, many pay only a superficial attention and do not retain much of that training. I see that as common nowadays with multi choice tests, all the student wants is to pass the test, not to learn the subject. However that is not restricted to newbies.
However experience is at least as important as training, in my own opinion it is much more important indeed essential. Even if the person knows nothing about what goes on in the electronics bay or hydraulic system, he will see what happens when he moves that switch or lever and build on that experience. Experience makes the difference between a trained and a competent pilot. Which one would you like to have sitting up front when you go on a flight, especially if the conditions are tough?
When all the flight crews are inexperienced (that will happen when the current crop of senior pilots retire at age 65 and is happening as we speak), how do the newbies get their experience? Who is going to mentor them, help them understand what they are seeing and how to handle the things that are not in the books? Picture the last two 737MAX accidents, and how different those would have turned out if the pilots had had experience of trim problems, either in the sim or in an airplane? And we, as pilots, are remarkably inventive when it comes time to find things to screw up.
Sure experience in a C172 is good, but it is not a replacement for the experience of a couple of thousand hours flying as crew in a B777, handling problems, learning when to start slowing down for the approach, how to handle an ATC delay on descent, how to save fuel when on a long flight and been held down due to traffic, how to cajole a better clearance, how to recognizer and fly severe turbulence or penetrate a thunderstorm without radar or any one of thousands of situations that are not covered in training.
Lets face it; the pilot you want to see up front has grey hair, a few lines on his face and a scruffy appearance. He (or she in some circumstances) will have experience. He cannot get that from a book, or a computer. He got it by doing the job. If he was a real pilot he would have been passing on what he knew to his copilot, giving that guy landings, approaches, some difficult decisions to make, and helping him/her to be ready to take over when it was time to give it up.
But now we have a huge hole in experience. The guys at the top are only (seemingly) interested in maximizing their income in their last few years before being forced to retire, and the ones coming up are so junior they do not understand what could be passed on to them, being solely interested in taking advantage of the opportunity to get something for free and without any effort on their part. They don't understand the importance of what they are seeing and lack the experience to pay attention. It frightens me to think that when the baton is passed, the commanders of those magic ships of the air will be so ignorant and unready, and mostly totally unaware that they are not ready because they did not get the chance to learn from those who could have taught them.
Without skill and experience we will become just the same as what we see now in those countries that have the money to buy airplanes and airlines but do not have the experienced pilots to fly them.