Every other exploit and virus is used by impatient idiots. NSO knows how to stockpile exploits.

I've been there done that. It's how we pretty much kept Wii homebrew available consistently throughout the console's life. We had the next exploit ready before Nintendo patched the current one.

Apple isn't involved. NSO are just good at their job.

Thanks for the explanation. It might seem obvious to people involved in this type of work, but I honestly found it hard to believe

...No, it is not clear.