Apple’s actually somewhat of an exception here. They actually make most of their profit from hardware, not services. In the first half of this year, Apple has made $167 billion in product sales, and $53 billion in services sales. Their cost of sales for products was $103 billion for products, and $13 billion for services. That gives $64 billion in profit from products and $40 billion in profit from services. So about 62% of Apple’s profit comes from product sales.

Teardown reports of iPhones indicate that an iPhone 15 costs $423 to make but costs $799, giving a profit margin of about 47%. This doesn’t account for shipping though, so the actual margin will be a bit lower.

Apple profits source Teardown source

Colorado?

You can use swift package manager to create an executable target, which you can then run on macOS from the command line. Most frameworks (aside from UI) are shared between iOS and macOS like AVFoundation. If you don’t have access to macOS, you can still use swift package manager to build and run code on Linux or Windows, though you unfortunately won’t have access to any Apple frameworks.

Metal — it’s a proprietary graphics API made by Apple

Hacking with Swift is a great resource. They have quite a few books related to development in Apple platforms (some free). You’ll probably want to do some research on if you want to learn SwiftUI or UIKit. UIKit is still used much more frequently in industry, but SwiftUI is becoming more mainstream, and is easier to learn. Hacking with Swift has books for both frameworks.

Personally, I’d recommend just jumping into writing a simple app (probably by following along with a tutorial) since you already know how to code, and have a grasp of the basics of Swift. There isn’t too much you need to learn about Xcode initially, and any tutorial for creating your first app should walk you through any Xcode specific steps you do need to do. Most of your learning will probably be related to either UIKit or SwiftUI, which are the frameworks you use for actually getting stuff on the screen. While learning these, you’ll undoubtedly pick up more knowledge about Swift and Xcode, which will improve those skills. I certainly don’t think you need to become an expert in Swift or Xcode before learning UIKit or SwiftUI. As you learn more, you’ll learn what areas you need to improve on, and can tailor your journey from there.