Why?

Async in Rust is hard. The biggest drawback of async is the fragmentation of the ecosystem. Now you have sync functions and libs, async functions and libs, and different runtimes that are incompatible and thus require dedicated libraries for I/O.

An anemic standard library for daily needs.

The steep learning curve before being productive.

When Rust makes the most sense?

• common core for cross-platform apps. Proton leads the way.
• system programming
• embedded development
• insane scale