I'm not sure I agree (or maybe I misunderstand--I assume you're saying "the tool needs to be standard"?), but people use non-standard tools in C all the time. Every build tool or package management solution in C is non-standard. Every memory analyzer or static analysis solution is non-standard.
I think the real impediment isn't related to garbage collection, but it's just ecosystem inertia and industry knowledge inertia--the same forces that inhibit Rust adoption or C++ adoption or Ada adoption. Does that seem reasonable, or am I misunderstanding? What do you think?