Why is BitTorrent banned?

I'm curious, why is BitTorrent often banned or restricted in certain regions? Could it be due to the sharing of copyrighted material, which some users may engage in? Or could there be other reasons, such as network congestion caused by the heavy traffic it generates? It would be great to get a deeper understanding of the motivations behind these bans and restrictions, and how they might impact the use of BitTorrent for legitimate purposes.