You should give it a try to compile other game engines, and compare them, Unreal Engine is a fun one with the source available, take a look how big their artifacts are :)

With that said, there are plenty of small game engines out there, but couple Rust's somewhat slow compile times with the ecosystems preferences for "many crates" over "one big crate", and yeah, even medium-scale game engines like Bevy take a bunch of time and space to compile. But it is a whole game engine after all, maybe not representative of general development in the community.