Unfortunately, I think one of their problems is that iPhones last too long. I'm still very happy with my iPhone 6. The spec updates aren't as tantalizing as they used to be.
No matter what stage of the project, you're implicitly writing code to a specific type whether you know it or not. Typescript just makes types explicit, and makes clear all the places you've made type assumptions. So if you need to change types later in the project, you can do so with confidence knowing that you've handled all the cases you made type assumptions.