Comment by Ygg2

> "gradual memory management" is the holy grail

I don't think gradual types are as holy grail as you make them out to be. In gradual typing, if I recall correctly, there was a large overhead when communicating between typed and untyped parts. But further

But lets say gradual memory management is perfect, you have to keep in mind the costs of having GC + borrow checking.

First thing, rather than focusing on perfecting GC or borrow checking, you divert your focus.

Second, you introduce an ecosystem split, with some libraries supporting GC and others supporting non-GC. E.g. you make games in C# and you want to be careful about avoiding GC, good luck finding fast enough non-GC libraries.