Openai wanted to buy them. G42 the largest player in middle east owne a big chunk. You are simply wrong about big investors not touching them but my guess is they will be bought soon by Meta or Apple.
I can't imagine Apple being interested.
Their priority is figuring out how to optimise Apple Silicon for LLM inference so it can be used in laptops, phones and data centres.
Either Apple entirely forfeits AI to the businesses capable of supplying it, or they change their tactic and do what Apple does best; grossly overpay for a moonshot startup that promises "X for the iPhone". I don't know if that implicates Cerebras, but clearly Apple didn't retain the requisite talent to compete for commercial AI inference capacity.
That said, Apple has some talented people already and they likely just need to iterate to make their designs better. Bringing new people on board would just slow progress (see the mythical man month).