The point is that they shouldn't be confused as having the same goal. The reason object capabilities are so difficult to integrate is that you basically have to refactor all of your software to use a different style of programming. I don't think that means that pledge is somehow superior. They do two completely different things.

For an example of an active project using ocaps see:

https://fuchsia.googlesource.com/fuchsia/ https://sel4.systems/