tl;dr: LLMs hit a productivity sweet spot in 2026 because they became reliable enough to run in automated feedback loops with objectively verifiable criteria (like "make a button that does X"), yielding roughly a 2x boost. However, they still struggle with subjective judgments like code maintainability and documentation quality, so the author uses them for rough drafts and explicitly tells them not to write comments or READMEs. Further model improvements likely won't deliver 10x—that will require the industry to retool workflows around current capabilities, not smarter models.