The WIN32 API has largely remained unchanged over the last 15 years while changing dramatically under the hood in its implementation. With the recent possible exception of Apple's recent bull run this is so far the most lucrative API in the history of the world. And it's made possible by the fact that all the key API elements are exposed only as opaque handles.
I could go on and on with examples like these that are about as far away from a minor bandaid as you can get.
There's also a difference between building good software and building profitable or even popular software. Sometimes bad design can even help maintain a product's market lead, as if a design is complex, it's hard for competition to make compatible products.
You're also still confusing abstraction and encapsulation. An API can be an abstraction over a lower-level system without being an example of encapsulation.