Learning new languages did change how I think about programming. For example, Clojure's immutability and functional nature had a strong influence on how I write my (mostly Python) code these days. I learned how to write efficient code for CPUs with C and C++, and for GPUs with CUDA and OpenCL. I learned math with Matlab and Octave, and declarative programming with Prolog.

With Mojo, on the other hand, I think a library (or improvements to an existing library) would have been a better approach. A new language needlessly forks the developer community and duplicates work. But I can see the monetary incentives that made the Mojo developers choose this path, so good for them.

"A language that doesn't affect the way you think about programming is not worth knowing." ― Alan J. Perlis