Ironically, that was the main interest of Brad Cox who, with Tom Love, created Objective-C, which was acquired by NeXT, and became the way forward for Apple.
In my experience, it is very hard to build a business around software objects. I spent a couple years trying to build an App around the Apple Watch. But, Apple only allows 3rd party complications. It is essentially a component. Apple recommends focusing on doing only one thing.
Moreover, as a component, you the developer often have less control over the UX. On the Apple Watch, when a user opens -say- Spotify on the iPhone, your app is kicked out.
So, a couple weeks ago, I decided to put the Apple Watch development on hold and do something else on the iPad.
