My knowledge is outdated, as I last seriously looked at it about nine years ago, but I doubt Binder is even better than dbus; it was not good. I'm quite surprised with people suggesting it. There was that recent kernel Binder bug even with the rust implementation. It was rewritten in rust because it has had a never-ending string of serious security bugs. On top of that, it had very poor throughput. I'm guessing this improved with the rust implementation.

It was a toy created by former OS devs who really didn't want to use Linux, but wanted their pet IPC from their former OS. It even used to be the case that Binder would dynamically create threads in the receiving process without userspace knowing. As in, your process would magically have function calls coming in from threads that you never created. Imagine the issues this can create with locking, forking, etc. This ended up being changed to get it upstreamed, but I consider this absolutely insane behavior.