I don't think many actually use the STL besides app dev's. Most systems dev's are targeting WIN32, RTL, UEFI, POSIX, BOOST, UNREAL, or something else. Not only this, but STL also breaks alot of things by what it puts in, Kernel, Unreal, and results in alot of usecases to not use the STL.

The only time in my entire career i've ever used the STL was in college. Since most C++ jobs are not Appdevs. All those have moved to C#, Go, or some other higher level language. Or again, just rely on the built in suite like RTL, Posix, Unreal