RE: Do we still need trainer aircraft??
The plane that taught me to fly was a Dave Patrick Ultimate Biplane w/OS 160. I bought that about 12-16 weeks after I flew for the first time. Now if there is any plane that is going to keep you on your toes for a new pilot that was the one. That DP Ultimate is what I owe my flying skills too as far as the field goes. It taught me all about precision and flying on the wire. You were forced to make perfect landings or else it was gone unlike a trainer which you can basically land with your eyes closed while throwing full deflection.
I actually tell my new students not to mess around with trainers at all. It's better to get something hotter like a low wing sport plane and a good computer radio. With a good computer radio you can make any low wing sport plane into a high wing trainer.