Yeah, i'm sure if it was capable of running macOS when used with peripherals (i.e. a smart keyboard with trackpad), it would be the form factor of choice for many more people.Don't disagree at all, really. However, the iPad's form factor has so much potential as the future of computing though, which is what makes it so attractive due to its flexibility compared to a traditional laptop. Infinitely more portable because of its notepad-like form factor, it isn't beholden to a keyboard and thus can be more easily used standing up, laying down, in cramped areas on a commute or waiting in line. It is basically better to use everywhere except sitting at a desk.
If it can also be good sitting at a desk with a keyboard, then it should be by definition the form factor of choice.
All that has really held it back is the software and OS features accessible to the end user. iOS 11 looks to finally be changing that limitation.