Private torrent communities are already reluctant to use x265 which provides marginal gains compared to x264 at a great increase in encoding time.
A part of the process in pirate movie encoding (p2p, not really scene) is testing optimal encoder parameters (adaptive quantization strength, psychovisual rate-distortion, quantizer curve compression etc) on short clips meant to be representative of the whole movie (e.g. 60 frames every 4000 frames). If encoding a single test clip takes an hour as with x265 that sure puts a damper on things.
About the only place in movie torrent communities where x265 makes sense is 4K encodes as x265 can retain HDR metadata (h264 can too to an extent with the 2017 revision to T-REC H264 but it's hardly supported anywhere).
This may be different for pirate _streaming_ services.