It doesn't answer the question, in part because the question doesn't make sense. (I just attempted to write my own answer, but as I explained within it, I'm stuck guessing what the asker is trying to do.) There are numerous hints in the question and subsequent comments that the asker found the wrong command for the job. The command they're running does something completely different from what they want to do, so asking why it's taking a long time isn't useful. When they try your command, it's still not going to do what they want.
There are some terminology issues with your post. I wouldn't warrant that worthy of a downvote--yes,
bs actually stands for block size, but it probably also affects the buffer size.
It's definitely not a great idea to pipe dd directly to another dd process, though I see where you got the idea; in your example, you've got another command in between. However, the example provided by the asker indicates that there's no need for an intermediary command--or, at least, that would be what it indicated if they were on the right track, which they're not.
When someone asks the wrong question, answers are inevitably going to be controversial. Opinions vary widely on how you should proceed. Some would rather that ignore the discrepancies and attempt to answer the literal question, thereby helping people who arrive from search engines. Others would rather that you read into the asker's intentions and provide an answer that helps the asker, rather than people arriving from Google. Still others want you to leave a comment and downvote the question.
In this scenario, there's no winning answer. You can see that my answer was almost immediately downvoted. It's probably going to continue to get downvoted.
Edit: I just saw someone mention the term "XY problem" elsewhere on AskDifferent. It's a pretty fitting explanation for the problem here.