Frankly, I don't really see how it isn't solved, even with the current state of LLMs. Frontier models can write, understand, correct, and optimize code in practically any language at a superhuman level. I haven't come across a single problem that LLMs can't solve. You can easily give them a research paper, ask them to implement it and in an hour or two it's done. Or even point them to a video or screenshot of something and say "implement this feature in our game engine" and... they just do it. It might not be optimally perfect, but what % of human written code is? Even if you ignore the time amortization (given how models can spit out weeks of human work in an hour) they still obliterate even an experienced developer.