Creating a future in Rust does not have any side effects like running the future in background. This is not JS. Creating a future is just creating an object representing future (postponed) computation. There is nothing spawned on the executor. There are no special side effects (unless you code them explicitly). It works exactly as any other function returning a value, hence why should it be syntactically different?
If you called something that returned a future but you forgot to use the returned future - how is that different from e.g. opening a file for write and forgetting to write to it or from creating a User object and discarding it immediately, forgetting to save it to a database? There isn't really a difference, and therefore all those cases are handled by `#[must_use]` warning.
Contrary, an `await` is an effectful operation. It can potentialy do a lot - block execution for arbitrary long time, switch threads, do actual computation or I/O... So I really don't understand why you want to hide this one.
Maybe the naming is confusing - because `await` does not really just `await`. It runs the future till completion. You should think about it more as if it was named `run_until_complete` (although it is still not precise, as some part of that "running" might involve waiting).