Facebook picked Rust to implement Libra
Bitcoin (Bitcoin Core) is implemented in C++. At that time, Go and Rust weren't born yet.The most popular Ethereum implementation (Geth) is written in Go. The second most popular Ethereum implementation (Parity) is written in Rust.Now, Libra is written in Rust.So I guess the moral of the story is, if you want to write a greenfield high performance application, Go or Rust should be your choice compared to C++.