Where’s the reference that Siri’s abysmal performance is from a lack of data? Apple might not have Google scale data but it should have enough to make it work through some sort of self-supervised/semi-supervised learning.
I am not an expert in this area, I’ll trust your word. I edited the comment. My guess was that Google has a knowledge graph thing and it’s been collecting people’s behavior for more than a decade. It's also their core business, for Apple, Siri is not.
I found a lot of value in your post, regardless of the Siri part. Manufacturing is hard.