It's true that this is an unsolved research problem, but as an ML researcher, I expect that some combination of better integration with existing information retrieval systems, a moderate amount of high-quality data, and some small but important tricks will solve it. I don't know whether the time horizon is six months, one year, or five years, but I'd be surprised if it takes longer than five. GPT-2, which was arguably the first LM that could sound human-like, is only four years old. Given the value of a trustworthy LLM, an enormous amount of research effort and resources will be directed toward this problem, and I don't think it's substantially harder than other challenges the ML community has solved over the last five years.
