On one hand it always saddens me to see more projects use Rust as it means that I won't be able to contribute to them as I won't learn that language.
On the other hand I also do not get why Rust is hyped. Not that I'm a big C++ fan, I'm more of an Ada kind of person, which is exactly why I don't get why Rust is supposed to be 'better'.
Rust doesn't have super strong typing of Ada, it follows by default more the dynamic typing of Python, its syntax is symbol-based and thus offers a severe learning curve over languages that use plain English (like Ada), it doesn't offer contract-based programming, access types for heap memory and on top of all that it doesn't follow a single one of the Steelman requirements, in particular the restricting of how many ways one can write the same code.
C++ is 'safe' enough that it has been certified by the DoD to be used to program the avionics of the F-35 jet. As someone who has plenty of professional experience in C and C++ as well, I can see how modern C++ (i.e. C++11 with standardised memory model) can totally work in safety-first applications. It's mostly about pushing the C baggage to the side, instead using the bits of C++ that do not allow you to easily shoot yourself in the foot.
Yet neither C, nor C++ nor Rust do much to prevent the most common kind of error that makes stuff catch fire in production: logic errors and faulty assumptions. Those incidentally happen to be the reasons why Ada requires explicit termination of blocks with a named end statement, why contract-based programming is part of the core language since Ada 2012 and why nothing is done implicitly. The compiler will bludgeon you over the head with 'are you really sure?' errors until you have addressed every single point.
So yeah, unless an open source project happens to be written in C, C++ or Ada, it might as well be closed source to me. And that makes me somewhat sad.