Both don't ship with their own Wayland compositor, but there are enough to choose from.
Xfce comes with a wayland session using labwc out of the box, but was also tested with Wayfire. The devs state you shouldn't hold your breath waiting for the native window manager xfwm to be ported into a Wayland compositor, since they don't know if/when it will be done. Almost all other Xfce components support Wayland now, while retaining X11 compatibility.
LXQt's newest stable release has full Wayland support, with 7 different Wayland compositors to choose from within a GUI settings menu: Labwc, KWin, Wayfire, Hyprland, Sway, River and Niri
https://xfce.org/about/news/?post=1734220800
https://lxqt-project.org/release/2024/11/05/release-lxqt-2-1-0/
sway, wayfire, river, hyprland and labwc are standalone wayland compositors. why we need desktop environments inside them!
You don't need a desktop environment, but it takes away a lot of config work if you want a full featured desktop.
Exactly, I used hyprland for a while but configuration is too time-consuming if you want a decent status bar, launcher, keybinds... So I'm excited to try it with LXqt, thanks for the heads-up!