Only because the technology was pushed forward and adopted for the masses.
P2P is used a lot of normal actives (Zoom, Discord, Games, Collaboration apps). It's just when it comes to sending large amounts of data, that Apple wants to have a say in it.
Oh sure, I use torrent for legitimate things as well, e.g. Internet Archive downloads and Linux ISO image downloads, and don't think that Apple should ban the apps. I'm just pointing out that the analogy doesn't work.
Funny that you mention normal activities that are all allowed on Apple as examples of good P2P uses. Most of the sending large amounts of data P2P uses are illegal file sharing.
I don't think Apple cares about sending data in general. Apple allows other P2P file sharing apps on the app store (Resilio Sync or Möbius Sync come to mind).
P2P is used a lot of normal actives (Zoom, Discord, Games, Collaboration apps). It's just when it comes to sending large amounts of data, that Apple wants to have a say in it.