And nothing of that has anything to do with understanding core concepts. Threads are native CPU constructs, they don’t just exist because of a library. Memory management is nice, but also not arcane knowledge that can only be learned by going to a university.

A C dev learning dependency injection and a Java dev learning manual memory management will both have to learn something new, but for neither it should fundamentally change how they think about computers.

Again, you seem not to understand what’s actually going on under the hood. There is not a single language concept that a regular dev in another language couldn’t understand. It’s all just “make compiler write assembly so computer go brrr”. That doesn’t mean it’s trivial to be proficient in a new language, but that was never the goal of any higher education. It’s called computer science, not advanced button pressing.