Rust is hardly groundbreaking. It's a mix of imperative/functional styles that are well known, thrown in with pointer ownership which has been researched and toyed with in various forms for years before. It's a small improvement on C and C++. Making a practical implementation is praisworthy, but I'd say this hardly counts as an invention in open source, and it's particulaly unrepresentitive of the FOSS community anyway because it's backed by a big company with a big research pot.

The kind of game changers Kay is talking about are not that easily approachable. You won't be able to take your existing knowledge of language X and suddenly see how they mostly apply to Y too. If that were the case then you've not really changed the paradigm, only given a glimpse of how it could look from the existing one.

And the reason you don't see many of these kinds of innovations in the FOSS world (although they definitely exist), is because they don't gain traction. If something is clearly new and takes significant effort to learn, very few people are going to take the time to investigate it. Meanwhile, solutions which fit well into the existing paradigm are easily accessible by masses of developers, and they flourish. This is probably one of the main reasons that real invention is rare: people are after fame, and adoption rates aren't going to go up quickly if you challenge existing conventions.