I do think SPARK is the best in terms of safety, but Rust also provides way better safety mechanisms than almost any other language, so I wouldn't discount it s

I do think SPARK is the best in terms of safety, but Rust also provides way better safety mechanisms than almost any other language, so I wouldn't discount it so quickly. Also Rust, I think, has much better developer ergonomics (outside of the delta types which I would really like to have everywhere), and to improve on the status quo we need something safer, but also something people will use. In the same vein it's useful that Rust is a bit trendy now, since you'll need a lot of people to advocate for this kind of change successfully. The worst outcome is sticking with C and C++ any longer. Perfect being the enemy of good shouldn't keep us here.