Chrome isn't going to adopt any Rust, and Firefox is a few percentilies away to matter at all.
Android now has Rust, yet it isn't exposed to app developers, NDK is all about C and C++, as is the newly introduced AGK for game developers.
AMD/Intel/NVidia now employ many of the ISO C++ contributors and are pushing on using standard C++ as the lingua franca of GPGPU computing.
Azure Sphere, being sold as top security IoT device, has C SDK.
The new WinUI / WinAppSDK are mostly coded in C++, with bindings for other languages.
Apple just released C++ bindings for Metal, as alternative to the existing Swift ones.
So, yeah their business units don't seem to be very keen in following the security advices anyway.
The analogy I see is an industry similar to the auto industry as it decides what to do with their ICE based platforms as consumers are going after all electric.
Regular consumers are going electric when they become cheaper and usable as ICE vehicles, until then they are fine for rich people with garage.
You can ignore those findings as you like, but that is why so many people are interested in Rust.