I think it is probable that pilot skills are deteriorating (along with pay) but I still fail to see what it has to do with this particular accident. If the plane flew into the ground and the pilots didn't notice because they were too enthralled with their cell phones that would be one thing, but all pilots involved in the three incidents understood what was wrong, the just didn't know what was causing it. Hindsight is 20/20; like viewers of a horror movie we know which door the monster is hiding behind, but the protagonists don't. The surving pilots identified the problem incorrectly but were lucky in that the actions taken to solve the nonexistant problem actually happened to solve the real one.
The poor pilots were at the root of a huge decision tree, and like they are trained to, attempted to find a solution in their procedures and manual. In this case it would have been better had there been no procedures or manual because they wasted time looking for information that was not there. A button that would have easily solved their problem (had they known about MCAS) had been disabled, leaving them having to figure out on the fly a "goldilocks" solution, turn off the electric trim immediately but not before using it to get back enough in trim to use the manual wheels, but not for too long or MCAS will reactivate (as it did.)
This was not a bad play on a football field that we are arguing about, 346 people lost their lives due to an entirely predictable engineering fault.