I could’ve spared two hours of googling if I had just known this.

I had this in my css file to disable text selection in my mobile-targeted web app:

* {
  -webkit-user-select: none;

This is nice and makes what is actually a website behave more like apps do. What I didn’t know was that this also disables text input on iOS.

Fast forward two hours: Either remove the * rule above or re-enable user-select for input fields:

input {
  -webkit-user-select: auto;