One day, long after I'm gone, people will finally accept that Python and JavaScript are no longer young languages.
JavaScript is 26 years old, Python is 31. They both continue to grow in importance year-on-year, JavaScript because there is nothing on the horizon which will plausibly replace it, and Python because a large number of industries and programmers genuinely love it.
I think there's a nontrivial chance they'll both still be languages of primary importance in 50 years, but I'd bet my bottom dollar that they'll at least remain as relics yet needing support the way Fortran and COBOL exist today.