The context makes it clear that what's meant is "strictly worse as a C++ alternative". Rust, like you said, isn't there yet. And I'd take issue with the claim

The context makes it clear that what's meant is "strictly worse as a C++ alternative". Rust, like you said, isn't there yet. And I'd take issue with the claim that the gap has been shrinking - C++ right now is developing at a faster pace than Rust.