And by that I don't mean using Rc<> everywhere nor do I even mean making a GC library and then using GC<> everywhere. I mean having the runtime handle all memory things with you having to think about it only when some extremely rare corner case breaks.
https://learn.microsoft.com/en-us/dotnet/standard/memory-and...
It's worse at dealing with ref structs so C# is better for some low-level tasks. But it has other niceties like IL-level function and lambda inlining.
Tho point of Rust is to be safe language without GC. Even if not perfect, best thing about Rust is borrow checker and border between safe/unsafe. You can use several other languages, like Ocaml, if you want Rust with GC.
I could imagine people want a programming language that is: memory safe, without GC pauses. A bit slower by default than C / Rust, but with the _option_ to make it as fast. Then easier to learn, less vendor lock-in than Swift, and a modern syntax (no null pointers etc).
I don't think such a language exists currently.