Absolutely this, the most recent example is the Dash fiasco. It turned out OK for the developer, but had he been only on iOS for example, Apple would've ended h

Absolutely this, the most recent example is the Dash fiasco. It turned out OK for the developer, but had he been only on iOS for example, Apple would've ended his source of income. They also add more and more hoops to install non Mac App Store apps with each macOS release, I mean you can no longer install apps from "Anywhere" for example, like you used to. What I recommend doing is to learn how to develop solid, cross platform APIs and you then have the flexibility to develop as many clients as you like, web, iOS, Android etc. with no single point of failure.