Obviously 99% of languages never make it at all, but Rust's adoption rate is worse than what the languages at the Go/Kotlin level -- i.e. those languages that aren't superstars but have achieved very respectable success -- had at that age. More importantly, most languages reached their ultimate "tier" by age 10 and virtually all (I think all but Python) have reached it by age 15. As of right now, its adoption doesn't suggest Rust is poised to replace C++, let alone do better. But yes, I agree that its prospects are looking better than Haskell's or Erlang's.

And again, the 5%/10% numbers were symbolic. 10% was meant to represent Go/Kotlin levels of success.