No, the difference is setup and client. Apparently my setup hides the spammer, yours does not. So, the protocol can definitely work, but as I said before, some clients might be lacking or needs a bit more work to set up in a satisfactory fashion.
If you want the protocol not to work, you sure can. But you can also make the protocol work. It's a choice. And yes, this is more work compared to using a platform, as you outsource that work to the platform overlords. The price you pay for the liberation of platform overlords is that you - and only yourself - have to take on that extra work to make it usable for you.
If you've been deplatformed before, you know which choice is more valuable.