It's not the devices, it's the app. Here at Medium, for example, an iPad is not ideal. There are things their app does poorly and other things where the browser fails. The Mac browser version does almost everything well, though you have to use both Chrome and Safari to be the most productive.

This is also found in other apps and in other tasks I do. Some things are best on one device, other things in another. For me, Mac, iPad, iPhone, and Watch let me work most efficiently. All are important.

It's expensive, of course.