By complexity I mean roughly the number of language rules / techniques / idioms a programmer has to understand and keep in their head to be able to program effectively. I would say this is far lower in C than in Rust. I do not see how the additional hoops Rust makes you jump through makes it easier to achieve a goal, but I see how it can help prevent certain errors (but not many others).

It also seems obvious that the problematic aspect of getting anything done in Rust is fully compensated by having a lot of libraries available quickly via Cargo, so people are essentially just assembling things at a high-level. And in principle, I think this is a very good thing, but in the way this is implemented it comes with severe supply chain risks.