I feel this might come down to the scope one has in mind when thinking of the word "interop". I think one can reasonably simultaneously claim that the interop "mechanics" are excellent in that it's generally possible to create a Rust library that quacks like a C library and that basically any C library is usable by Rust code, but the interop "ergonomics" are suboptimal in that (as you say) actually writing the glue code can be a bit of an adventure.
I think that's a fair assessment. To your point `cbindgen` makes the mechanics of the whole thing painless & linking was trivial. That's worth a lot especially when compared to other languages.
