I actually used to agree that Rust generally wasn't good for high-level application code, but working with Bevy has made me change that opinion for certain domains. I simply haven't seen a system that makes automatically parallelizing all application logic (game logic, in this case) feasible, other than Bevy and other Rust-based systems. The trick is that the borrow check gives the scheduler enough information to automatically safely determine which systems can run in parallel, and that's very powerful. It's not that you couldn't do this in C# or whatever--it's that you won't without a system that helps express your intent and enforces that those declarations are up to date.
For applications that don't need high performance for the CPU code and aren't systems code, sure, Rust may not be a good choice. I'm not writing the server-side code for low traffic Web sites in Rust either.
For applications that don't need high performance for the CPU code and aren't systems code, sure, Rust may not be a good choice. I'm not writing the server-side code for low traffic Web sites in Rust either.