Being the host of an educational podcast, you would think I'd be iOS only at this point. I'm not, and I'm much more closely tied to requiring a Mac vs requiring an iPad to effectively do my job.
Website Content Management
During my day job, I manage the backend of websites. This isn't writing code, but updating content. This does require a lot of text selection, though. I still find text selection to be quite cumbersome on iOS. In Wordpress especially, some custom pages have "content blocks". These blocks are near impossible to work with on iOS. Is this the fault of iOS? No, but I'd like to see Safari bridge the gap with this regard. We've given it enough time that I feel confident that the creators of these content management systems and plugins are not going to be build for iOS management, so I believe Apple should build some sort of "Desktop" mode for mobile Safari to make it look and behave more like a traditional desktop browser.
Most of the website management apps are built around publishing blogs, but not actual site management.
Ideally, all of these web companies would build native iOS apps that could take advantage of all that the devices have it offer. Since they haven't, it's time for Apple to take control of the issue.
I stand in front of a 13" MacBook Pro with a 24" external monitor all day. I have both displays at eye level, and I have my trackpad and keyboard (external) at the proper height. I'd like to be able to plug an iPad Pro into an external display and be able to interact with it from an external keyboard + input type device. I finding using iOS for extended periods of time puts strain on my shoulders and neck. What would this look like? I have no idea, but I'd love to see something.
I'd love to go iOS only, but these are the two big things holding me back.