Is there a very clear explanation of who gets charged & who doesn't? From what I understand places like Amazon don't get charged for in app purchases, but Audi

Is there a very clear explanation of who gets charged & who doesn't? From what I understand places like Amazon don't get charged for in app purchases, but Audible (owned by Amazon) would & so they don't offer buying books. I assume finance stock/crypto/etc apps don't get charged. I've heard that food & drink, taxi services, & house rentals don't get charged. -- I could be mistaken about many of these above.