My bad. I can’t find the actually video but there exits a startup that shutdown because Rust/WASM performance wasn’t any better on top of that it’s was harder to develop with Rust. But as my edit to my previous comment shows things got better for Rust. It’s no longer the case.
Nix is not transitioning for the last 20 years. The community recently had a lot of discussion lately and starting towards a better path. It’s moving at such a pace that even official wikis maybe be out of date.
Of course I cannot say if this change will fit your particular needs. As someone who tries new things but not always gets success I understand your frustration.