It's been supported by qBittorrent since 4.4.0 released in January 2022 when built with libtorrent 2.0. The official docker images still use libtorrent 1.2 though as that is the default.

Probably not a dealbreaker for most but it might be hindering Bittorrent v2 adoption.

hmm... I just checked the (official?) macOS build and it uses 1.2.20.0 so there's that.

Looking at the downloads (I'm using brew) it seems that not many people uses libtorrent2… (https://sourceforge.net/projects/qbittorrent/files/qbittorre...)