Seems weird to comment on delayed new features from Apple. Obviously if it doesn't meet the quality bar it would get pushed back, that's just how they do things.
But I wonder how much of the problem is due to trying to minimise data processing off-device. Even with Open AI as a last resort, I don't imagine you get much value choosing betwixt the local model or a private cloud that doesn't save context.
Meanwhile the average user is yeeting their PII into Altman's maw without much thought so Siri is always going to seem rubbish by comparison.