There is a difference in C and Rust culture. Embedded C projects rarely have external dependencies, and in rare cases when there are dependencies (e.g. most projects use vendor SDKs nowadays), they are pinned and there is an expectation of API compatibility anyway

Rust on the contrary incentivises using dependencies, and especially embedded software is hard to write without using external packages (e.g. cortex-m-rt, bytemuck and many others)