They'd be 10x better than us already if task tedium was the problem. It's design sense that they're missing.

I find that in the areas where people think that LLMs excel at coding and don't like doing manually it's usually because the human was inclined to slop out repetitive boilerplate and thought that was the only way. Tests are usually like this, sadly.

LLMs are definitely good at providing reams of duct tape (which is drudge work) to patch up those bits of the code base where the code sucks. The problem is that duct tape is not the most architecturally sound construction material.