In absolute numbers I’m not sure that’s true. But 4GLs aren’t what replaced assembly for anyone. C, C++ and Pascal were the most common assembly replacements.

As for C and C++, there definitely aren’t fewer of them in absolute terms. And even in relative terms they are still incredibly popular.

All of that is beside the point though. The hype around 4GLs wasn’t that they would replace older programming languages. The hype was that they’d replace programming as a profession in general. You wouldn’t need programming specialists because domain experts could handle programming the computer themselves.

This is exactly the same hype around AI coding.