I'd say COM is also run-time type safe casting, and importantly the reference counting is uniform which might help writing wrappers for dynamic and garbage collected languages.

I'm still not sure that it brings a lot to the table for ordinary application development.

It's been a while since I've written it professionally, but I felt the fact that it has consistent idioms and conventions helped me be somewhat more productive writing C++. In the vast landscape of C++ features it winds up making some decisions for you. You can use whatever you want within your component but the COM interfaces dictate how you talk to outside.