The main failure in mail standards is a lack of explicit utf8 clean support lhs@rhs -if this got fixed (it's often called universal acceptance) a lot of things about mail as an ecology would improve. I have view on the spam thing. The whole "your idea will not work because" meme is hugely destructive of innovation in email. It sucks energy and mindshare. It's classic old timer put down. What would (imnsho opinion) ha…
If paying to send email is your suggested solution, I can see why you don't like the meme in question. But the suggestion is rife with problems. How exactly are you going to get everyone to start paying for email, which is free today? If it's a parallel system, how are you going to get people to switch? Who are they going to pay?
The sender pays the reader. If the reader is the one deriving the value from this communication, they would pay the sender out of band as compensation.