I have the same problem and am regularly `cargo clean`ing hundreds of gigabytes of build artifacts. It is a real problem. I feel like I need minimum 4TB of SSD space just to comfortably work at the scale I'm working now in Rust. That's just for the working space of the target folders across worktrees.
I just think agents benefit a lot from having unavoidable feedback in the dev loop, and Rust affords that through its strictness. It's easier for agents to fall into the pit of success with Rust. I do think it's somewhat lacking in compile-time features, though.