My understanding is Google Pay, Samsung Pay, etc allow Google and friends to track your CC purchases because of the way it's designed, where Apple Pay is designed in such a way that Apple can not tell who you are spending your money with.
source on this? AFAIK apple doesn't share it, but they definitely have access to the data.
I can't find the page describing the program on Visa's website, but their privacy opt-out describes it pretty well [1].
Carrying 800 grams of coins around me all the time sucks.
Once again Apple's marketing makes people believe things that aren't true, without actually lying.