Exactly, that's why they never made music players or cellphones...
A solved problem doesn't mean it's solved within their ecosystem and making them money. You can go out and buy a Google or Amazon device to do many (or even all) of the same functions, but that's not making Apple money, and they rarely integrate well with Apple's other devices and accounts. This isn't confusing.
On the other side, we all have to admit that solving this problem in the Apple ecosystem has significant benefits for the user: 1- Useful for Apple users, obviously 2- The most important, a close system with soft and hard integration could make things work much better and improve Google and Amazon propositions.
And... ok make more money for Apple. But it will be fare if Apple is more useful for the user.