You’re really stretching here. Ad companies make their money by selling ads; compare how much of Apple’s revenue comes from selling ads (very small %) vs how much of Google’s revenue comes from selling ads (almost all of it).
Prompts to buy additional products do not make a company an advertising company. If it did, every restaurant in the world would be an “advertising company” because wait staff, cashiers, and menus encourage customers to order additional food.
The App Store is a list of ads, on which Apple earns a commission. I don't think it's a stretch to see it as an advertising platform.
1. Apple Displays ads (Sales content for products.)
2. Apple gets paid when those ads convert into sales.
If Apple didn't get paid when Apps were sold through the app store, then I could see how it isn't an ad platform for them. Yet, the only option, if you want to sell a product listed on the app store is to pay Apple their cut, which fundamentally turns it into a paid advertising platform controlled by Apple.
While Apple is not considered an advertising company today, they have been growing services revenue for the past several years. Part of that is growth in ads (3rd party ads in app store, 1st party ads in the OS, iAd [discontinued], etc).
Even if rank and file Apple employees do not want to grow ads in iOS/App Store, clearly Apple leadership wants to sell more ads (and increase their services revenue). At App Store scale, their volume of ads is not trivial.
Curious if you'd say the same about Microsoft Windows. They never show banner ads anywhere in the product but they do advertise their own apps and services (and like the App Store on iPhone, they advertise apps you can install from their Microsoft Store).
IMO, both Microsoft and Apple are showing me ads I don't want to be shown.
Prompts to buy additional products do not make a company an advertising company. If it did, every restaurant in the world would be an “advertising company” because wait staff, cashiers, and menus encourage customers to order additional food.