> I believe that the fanatics in the rust community were the biggest factor.
I second this; for a few years it was impossible to have any sort of discussion on various programming places when the topic was C: the conversation would get quickly derailed with accusations of "dinosaur", etc.
Things have gone quiet recently (last three years, though) and there have been much fewer derailments.
As an outsider, I don't really see Rust having done anything different recently than they weren't doing from the start.
What seems to have changed in recent years is the buy-in from corporations that seemingly see value in its promises of safety. This seems to be paired with a general pulling back of corporate support from the C++ world as well as a general recession of fresh faces, a change that at least from the sidelines seems to be mostly down to a series of standards committee own-goals.
I'm not sure that there is a recession of corporate support from C++. Just that the proportion of companies that need C++ is smaller than it once was.
I like the safety promise of Rust. But the complicated interop story with C and C++ hurt it a lot. I mean, in a typical codebase, what proportion of bugs will be memory-safety related vs other reasons? Ideally, we could just wrap the safety-critical bits in a memory-safe wrapper and continue to use C and C++ for everything else.