Rust will not "flatten" Go. They have some overlap but generally don't serve the same purpose and don't appeal to the same crowd. Go's popularity is undeniable, both in open source and in the industry. Outside of major shops and the odd shady Fintech startup, there are still very little Rust jobs out there. It's not necessarily bad, it's just the nature of it. Rust adoption is a slow thing because it addresses problems faced by slow moving software.