When I first learned programming, I was focused on one programming language. And that makes sense for all new people to programming. There is a lot to take in. In addition to programming fundamentals, there are plenty of programming language warts to get through. Each language has them, and it’s valuable to worry about just one language’s warts, rather then try to work through all the new stuff your learning.
After I learned the fundamentals of programming and moved on, a specific programming language was no longer that important. The fundamentals translated from language to language fairly easily, and the warts of the language were just that; language warts. I could now see past them because I understood the fundamentals.
Syntax is an abstraction. It’s just sugar on top of more complicated, and hard to read source code. Really, syntax and all the language specific stuff isn’t that important. Any competent programmer can pick up a new language and do something non-trivial inside of a week. This, of course, assumes that the programmer has the time given to work through the language. What I’m really saying is, if you hire a competent programmer that doesn’t have any experience in the tools you use, and you give them a week to work through the language/framework; they will be productive by the end of the week.
Or a framework.
Or a library.
Or any other thing that an employer thinks is a prerequisite to hiring someone.