>The question really is why is swift <-> objc bridge so bad you need this software?

HUH? I don't even understand the question. A bridge is something redundant in itself. It doesn't have to be "so bad" to want to get rid of.

Why keep going through a bridge when you could (after this effort) call the lib directly?

And why maintain the same code in 2 different languages, an increasingly deprecated one, and your new one?