Yes, I thought about this too. Also LLMs can or will be able to translate from one language to another, so perhaps the fact that LFortran/LPython can translate Fortran/Python to other languages like C++ or Julia might not be useful.
My approach is that it is still unclear to me what exactly will be possible in the future, while I know exactly how to deliver these compilers today. I suspect a traditional compiler will be more robust and also a lot faster than an LLM for tasks like translation to another language or compilation to binary. And speed of compilation is very important for development from the user perspective.
Conclusion: I don't know what the future will bring, but I suspect these compilers will still be very useful.
Some IDEs have incremental compilers that are sufficiently fast to update squigglies and what-not on every keystroke. Compilation speed is a primary value, in general.
My approach is that it is still unclear to me what exactly will be possible in the future, while I know exactly how to deliver these compilers today. I suspect a traditional compiler will be more robust and also a lot faster than an LLM for tasks like translation to another language or compilation to binary. And speed of compilation is very important for development from the user perspective.
Conclusion: I don't know what the future will bring, but I suspect these compilers will still be very useful.