A fresh installation of opensuse Tumbleweed Snapshot20230522 Gnome role ships pipewire-pulse.
Yet neither pipewire nor pipewire-pulse seems to be running with a realtime priority, only an elevated niceness of -11. What gives?
The pipewire package explicitly requires rtkit. The pipewire module RT is responsible for configuring scheduling policies.

> # cat /proc/1469/sched
> pipewire (1469, #threads: 2)
> policy                                       :                    0
> prio                                         :                  109
> # cat /proc/1473/sched
> pipewire-pulse (1473, #threads: 2)
> policy                                       :                    0
> prio                                         :                  109

The logs of rtkit-daemon also indicates that a request for realtime priority was issued for children threads but those threads do not appear to stay around.

From all the documentation I have seen, pipewire *should* attempt to gain realtime priority. https://docs.pipewire.org/page_module_rt.html