iPhone, iPads and MacBooks are all computers, the problem with legacy computers like the desktops and laptops, is that they are not widely used anymore. 20% of all americans use their cellular data as the single source of Internet access. Data usage is rising rapidly each year and has been more important than voice for the last five years. The freedom of not having cables or wifi access points is the primary reason to get one of these devices. Not having to have multiple subscriptions, receivers and devices is probably the greatest drive behind the rich and populous Internet that we have today.
As much as I want another MacBook Pro to be released, the future is not looking bright. We already have a very competent MacBook Pro from 2015 that will do 99% of the tasks required of it, but I guess we want new toys with new names more than what is adequate. Still the numbers from content consumption tells us that we are moving away from from laptops and desktops as our primary computers. Most of the content is served to mobile devices. I can buy an iPad with cellular sim slot and get a subscription from a tele company within minutes. On the other hand, if I want access to the Internet on a legacy computer, I am dependent on routers and ISPs, which can take up to 30 days to install.
Computers with a mouse/trackpad and keyboard may be the best overall tool for creating and managing content, but may be too much for those of you that exclusively consume content. Even though you can upload pictures, draw and write moderate amounts of text on a mobile device, there is a limit to how much you can do on devices with less ways to input as well as limited connectivity. As content and it's management becomes more complex, there is certainly a need for a proper computer like a MacBook Pro or Mac Pro. It seems right now that the current offerings are sufficient as far as Apple sees it, and the profits lie in the 99% of the population who consume rather than create.
I guess they are no longer making products for the crazy ones.