[pid-1]

Look at bittorrent. While it's impossible to kill it, targeting agregation platforms definitely made the protocol immensely less relevant than it was 20 years ago.

[codebje]

BitTorrent made itself less relevant by relying on end to end networking and symmetrical links, neither of which panned out.

[Osiris]

Such as? The Pirate Bay still exists as do thousands of other websites listing torrents.

BitTorrent traffic went down as streaming services increased.