It hasn't and likely never will because it is a structural part of how AI works.

You can see proof of this if you ask it obscure enough questions. That doesn't mean obscure scientific questions, I asked it questions regarding ship fits and modules in EVE Online, which is an extremely well-documented videogame. There are hundreds of online tools to help you for different things, mining yield calculators and more.

Well, ChatGPT just made up almost everything. Very confidently. It couldn't even get the damage types right, I was quite shocked.

Hallucination has only be solved for extremely narrow sets of problems, and only partially. Coding is one of those problems.