He characterizes the change as a move from frequent mistakes to tools usable day to day.
The same source places that capability shift beside an unresolved deployment constraint: sandboxing and agent security. Willison notes that roughly 40 of 277 conference sessions touched those subjects, while the serious agent-security incident he had predicted had not materialized.
Public source: https://simonwillison.net/2026/Sep/27/2026-in-llms-so-far