You're not wrong here. Not that I'm entirely up-to-speed on all of the deep Rust discussions, but the sense I have of the language evolution is that while there is definitely a loud contingent of people pushing for a lot of the complexity of full effect systems or linear types, these sorts of proposals aren't actually all that likely to actually move forward in the language.
(I should note that of all of the features mentioned in this blog post, the only one I actually expect to see in Rust someday is pattern types, and that's largely because it partially exists already in unstable form to use for things like NonZeroU32.)
Yoshua works directly on developing the language, and mentions he is working on these features specifically (he is part of the effects initiative), I'm not sure you won't see these features in Rust.
Yoshua is part of the "loud contingent" being described. He's not on the lang team, and he's been "working on" things like keyword generics for years without any indication that they are going to make it into the language.
> We (Oli, Niko, and Yosh) are excited to announce the start of the Keyword Generics Initiative, a new initiative 1 under the purview of the language team
https://blog.rust-lang.org/inside-rust/2022/07/27/keyword-ge...
Maybe he's not on the language team (I haven't read enough into Rust governance structures to know definitively) but it's not like he's on some random person working on this. And yes, work takes time, I actually disagreed with his initial approach where his syntax was to have a bunch of effects before the function name, and everyone rightly mentioned how messy it was. So they should be taking it slow anyway.
What complexity?