It's already in use at least it automotive. If you are not working with safety critical systems (ADAS type) Rust and to some extent embassy is already in the wild. Companies like ETAS (https://www.etas.com/ww/en/) or Ferrous (https://ferrous-systems.com) are working to certify Rust and some crates (embassy is there) to be used with safety critical components. It's not question if but when it will be used. Volvo, Renault and some Chinese brands already ship cars with Rust embedded components in non safety critical path.