I don't think that's necessarily what the OP is saying. I agree with OP.
Finding documentation to learn to use this absolutely obscure system is near impossible. I seen an announcement about a Pharo release a couple years ago and was like "huh, that sounds cool." Proceded to download it and had no clue about anything. It is not at all like any other IDE.
Learning it might not be hard, but when the IDE is absolutely different from anything else you've ever used, combined with very little documentation that speaks to how to do the basics, it can be a very mysterious and difficult thing.
Rust is like any other programming language, in that you write code in a file, then compile it. Yes, there's other stuff to deal with in between and it can get way more complicated. But the IDE is the real culprit, combined with documentation for a developer to learn to develop real applications with, that makes Pharo infinitely more difficult in my personal opinion.
I guess to simplify this a little with an edit. If you already know another programming language, learning Rust is not fundamentally different. Some parts of it will be difficult like the borrow system and stuff that's very Rust centric. But in most ways it behaves like a lot of other languages in terms of using it at a bare bones basic level. Pharo is ... otherworldly in that nothing else really compares, you have to learn a completely different paradigm for how to program it, and that is the difficult part imo.