Surely not "because of the borrow checker", since it's trivial to relax its enforcement with very limited runtime overhead. The tasks that essentially require G

Surely not "because of the borrow checker", since it's trivial to relax its enforcement with very limited runtime overhead. The tasks that essentially require GC (and this is pretty much always the case, even wrt. C!) are those where you're dealing with general graphs, potentially with cycles, and where the overall profile is such that you can't simply deal with it by allocating everything within an arena and then wiping it when you're done. This is where something like LISP traditionally shines, but Go of course ships with a well-designed concurrent GC that makes it a viable candidate in this space.