1. I don't think that bitcoin is complicated to learn,all one need to do is to learn the basic of bitcoin, which is how to buy and sell,transfer from one wallet to another and how to keep your noncustodial wallet safe from hackers. The technical aspect is hard for those that are not computer programmers and non science people.
4.OP, you should also know that bitcoin isn't legal yet in some countries which will be a big challenge for bitcoiners to teach people about bitcoin in such country. What you said is nice but it can only be achieved in countries that bitcoin is legal and I believe that in those countries that cryptocurrency is legal the adoption is increasing day by day.