Steve Jobs passed away the day after Siri’s release, and I don’t think anyone else had the confidence and internal credibility to push the hard organizational changes Siri needed, similar to when he moved Apple to a single P&L when he returned.

Until LLMs came along, there wasn’t much you could do to improve Siri’s underlying technology. You could throw a thousand monkeys at to add more phrases it could match on and improve the interface to let you know what you could do. But that’s about it.