@JeremyCherfas Re: languages, most new languages aim to be general-purpose and so are not so task-focused as say AppleScript or Snobol. It’s often then not the language itself that gives the benefit in switching languages.
Some languages are insanely complicated of themselves, but as someone who picks up languages easily, I want to direct your attention to what I view as both the source of much of the benefit and the time cost of switching languages: Mastering the standard library.
Languages with ridiculously little syntax, like Lisp, Forth, and Smalltalk, help make this distinction clearer if you try learning them. Extra clear when there is no single standard library, or that library is anemic and there’s a panoply of third-party options (hi, JS + NPM!).
(The main reason most people switch languages is probably neither language nor stdlib, though: It’s instead “what platform does it target” and “what option has the biggest community & docs for my use”.)