The languages do not die in one day. In 30 years, maybe there are some people writing new code in C++38... and of course the immense code base already existing will stay for decades.

What happens, is there is a steady descent in the number or people using it. I think it has started.

I know even C++ fanboys/lawyers, that are having a lot of trouble to keep up with all features from present and past... And 99% of developers I know, even very good ones, speak of "my 20% C++". So my feeing is 17 is the last version which some people can use 100% of.

Not wanting to do public shaming, there are still tutorials being uploaded to YouTube using Turbo C++ for MS-DOS.

While on the other hand I also have an issue keeping up with my 20% of JVM, CLR, V8, Azure, AWS,...

I guess things eventually implode and we need to start from scratch.

Those Turbo C++ tutorials tend to come out of India, and it’s because their schools are stuck teaching that. But those aren’t really tutorials for modern C++, they’re tutorials for C-with-classes at best.

Definitely, however many beginners don't know about it.

Imagine a group of teenager, getting interested into C++ via the Arduino or Pi based school projects, they search YouTube for tutorials (as common practice nowadays) and land on such tutorials.

That's not an hypothetical btw, I had students in France who fell into this