Reference counting can be used as an input to the garbage collector.

However, the difference between Arc and a Garbage Collector is that the Arc does the cleanup at a deterministic point (when the last Arc is dropped) whereas a Garbage Collector is a separate thing that comes along and collects garbage later.

> If you need a referecne counted garbage collector for more than a tiny minotiry of your code

The purpose of Arc isn't to have a garbage collector. It's to provide shared ownership.

There is no reason to avoid Rust if you have an architecture that requires shared ownership of something. These reductionist generalizations are not accurate.

I think a lot of new Rust developers are taught that Arc shouldn't be abused, but they internalize it as "Arc is bad and must be avoided", which isn't true.

> whereas a Garbage Collector is a separate thing that comes along and collects garbage later.

That is the most common implementation, but that is still just an implementation detail. Garbage collectors can run deterministically which is what reference counting does.

> There is no reason to avoid Rust if you have an architecture that requires shared ownership of something.

Rust can be used for anything. However the goals are still something good for system programming. Systems programming implies some compromises which makes Rust not as good a choice for other types of programming. Nothing wrong with using it anyway (and often you have a mix and the overhead of multiple languages makes it worth using one even when another would be better for a small part of the problem)

> I think a lot of new Rust developers are taught that Arc shouldn't be abused, but they internalize it as "Arc is bad and must be avoided", which isn't true.

Arc has a place. However most places where you use it a little design work could eliminate the need. If you don't understand what I'm talking about then "Arch is bad and must be avoided" is better than putting Arc everywhere even though that would work and is less effort in the short run (and for non-systems programming it might even be a good design)