I can see it being useful for summarization, or creative writing. What makes you so sure that LLMs will be useful _for programming_ in the long run?
All tools I mentioned before were useful for programming. They didn't got worse. Still not enough to keep them relevant over time.
I chose those tools as an example precisely because, for a while, they achieve widespread success. People made awesome things with them. Until they stopped doing it.
What brought their demise was their inherent limitations. Code by humans on plain text was slower, harder, but didn't had those inherent limits. Code by humans on plain text got better, those tools didn't.