Cargo is really simple, which is great, but also limiting. Maven is much more complex, but for good reason - there's use cases, especially around multi-artifact projects and version sharing, where cargo would require either some glue or you run into some interesting edge cases. Usually, Rust isn't used for the kinds of big, wacky projects with a million dependencies that companies write in Java/Kotlin, so those kinds of use cases are considered more unusual.

Gradle, in my opinion, makes itself complex because it's all code, is very brittle, and several of its features just don't work right and require workarounds. When it works, it builds fast and it works well, but getting it to work, and how often you have to get it to work again...not worth it.