safe Rust isn't just the borrow checker, it's also:

  - no uninitialized memory
  - clone vs copy semantics as part of the type system
  - Send, Sync, "fearless concurrency"
  - no unchecked indexing
  - type safety (you can't just cast things like in C)

I do think these are clear complements to a borrow checker, since it's all in the interest of preventing undefined behavior. Yet, there are even more nice modern features of Rust that C lacks:

  - hygienic macros
  - namespaces
  - pattern matching
  - modern build/package system