If what you are saying is true, then you would see exploit marketplaces list iOS exploits at hundreds of millions of dollars. Right now a cursory glance sets the price for zero click persistent exploit at $2m behind Android at $2.5m. Still high, and yes, higher than five years ago when it was around $1m for both, but still not "largely crushed". It is still easy to get into a phone if you are a state actor.
Yes, that’s the complicated part. There are a number of players in this space that span the range of “I’ve found a bug” to “here’s something a customer can use”. Each gets progressively more money for the value add. You can capture more for yourself if you do more of the steps. Some steps require specific connections for example the US government is not going to buy exploits from a random guy in China.
