One of the biggest criticisms made of iOS is that it doesn't support the use of an external mouse or trackpad. That means that even if you connect an external display and keyboard, you can't really use them as a "proper" PC. But that's not strictly true. It turns out there's a trackpad mode, that's been around for a while, that turns the keyboard area into a trackpad. And, in the soon-to-be-released iOS 12, it can even be used to select text, as well as move the cursor around the screen. Here's how it works.
When you tap hold on the iOS keyboard, the letters disappear from the keyboard and the entire area becomes a trackpad. You can then move the cursor around the screen. I find it much easier than tapping on the main part of the display and using the loupe tool.
When you're in trackpad mode, tapping on the display with another finger lets you select text.
All that remains is the ability to actually connect an external mouse and trackpad. By the way, if you spring for Apple's Lightning to USB Camera Adapter, you can connect a USB keyboard to an iPad
With 3D Touch potentially being dropped from the iPhone when the new devices are released next week, Apple needed a way to invoke text selection without the need to use the poorly utilised 3D Touch feature. It also suggests a further consolidation between iOS and macOS as the two operating systems become more and more alike with each generation of software.