I agree, mostly. The fundamentals of programming are more important than obscure specifics of a random language. Still, it's obvious not every language is suited for a specific task.
I don't mean you wouldn't build a web app with only SQL, but more subtle differences. Javascript is great for front-end, and has proven its worth at the back-end too. But a few months back I tried creating a (multi-threaded) web scraper with JS and NodeJS, but it kept falling apart. It mostly couldn't handle the amount of data and the multithreading was quite hard to get right.
I eventually did create a working version, but it did require a lot of learning about specific NodeJS implementations of streams and multithreading.
Later, I recreated the scraper in Python, which was a lot smoother experience. With JS I felt like I had to fight the language to get what I wanted. I didn't have that with Python.
Recently, I've started to recreate the project again, but now in Golang. This seems to be a lot faster, while the developer experience is still great.
I started with JS because I thought I knew enough of the language to complete the project successfully. But along the way I discovered not every programming language is equally equipped for the task at hand. And although I didn't know the languages, creating the scraper in Python and Golang took a lot less time to get right.