I have installed Pipewire succesfully on several Rapberry Pis, and also
an old Acer laptop, and it all worked first time, and is still working.

Here are the Wayland-free instructions for XFCE:

$ doas apk add pipewire wireplumber
$ doas apk add pipewire-alsa pipewire-jack pipewire-pulse
$ doas apk add pavucontrol xfce4-pulseaudio-plugin

$ mkdir -p ~/.config/rc/runlevels/gui
$ rc-update add -U pipewire gui

log out/in to test; reboot to make sure


However, today I noticed the following error on the laptop, not seen so
far on the Pis:

 Jul 14 11:27:45 sakomoto daemon.err pipewire[3030]: You are attempting
 to run an openrc service on a
Jul 14 11:27:45 sakomoto daemon.err pipewire[3031]: system which openrc
did not boot.
Jul 14 11:27:45 sakomoto daemon.err pipewire[3032]: You may be inside a
chroot or you may have used
Jul 14 11:27:45 sakomoto daemon.err pipewire[3033]: another
initialization system to boot this system.
Jul 14 11:27:45 sakomoto daemon.err pipewire[3034]: In this situation,
you will get unpredictable results!
Jul 14 11:27:45 sakomoto daemon.err pipewire[3036]: If you really want
to do this, issue the following command:
Jul 14 11:27:45 sakomoto daemon.err pipewire[3037]: touch
/run/user/1000/openrc/softlevel

This might be teething troubles with the user service stuff, but I
thought I would post it here just in case.  Again, as far as I can tell
it is still all working.

Cheers,

Ian.