Thinking about this, for me it’s the wrong question. Why SHOULD I go iPad-only or iPad-primary? What will the iPad do for me that my MacBook Pro can’t do?
For three to five days of the month I need to be as productive from conferences and hotel rooms as I am in my home office. For that reason, it’s helpful to have the same computer in my home office as I use when I’m mobile.
I like my iPad fine or reading, social media, and for short bits of writing, such as (again) social media. But the MacBook Pro is my workhorse. If it ain’t broke, don’t fix it.
I could see using an iPad as my mobile device if the iMac was my primary computer. But I’d be leery of doing that given my travel schedule and my needs when traveling.