Some interesting perspectives.

The last paragraph seemy poorly written, though. IIUC the author criticizes OOP for having a limited view of abstraction as only categorization? Specifically, ignoring other kinds of abstraction mentioned earlier.

I really liked the inverse relationship of extension and comprehension. To me that was the hidden gem in that article

Agreed. It is one of these things that are very clear after hearing them once. It is a good angle on some problems I have dealt with and I expect it to be useful in the future.