Richard Stallman was right since the very beginning. Every warning, every prophecy realised. And, worst of all, he had the solution since the start. The problem is not Richard Stallman or the Free Software Foundation. The problem is us. The problem is that we didn’t listen.
I am actually agreeing with you, it is not impossible.
However, given that Javascript is ubiquitous in the internet nowadays, giving it up would mean practically having to forego the “normal internet experience.” Not many people are willing to go that far.
I am not saying he is wrong. I am saying that there are people like me who, despite not being prepared to go as far as he did, still recognize that he’s right about such things.
For most people Free Software is probably a journey. You can improve your freedom gradually by slowly removing more and more proprietary software. The goal is to have as much freedom as possible. Javascript is at least sandboxed, so it won’t be able to do you as much harm as a regular program. I can’t stop using it either for now, but that’s the only proprietary software I use. Most people aren’t even willing to install a free operating system though.