It seems for some reason your pipewire session manager, wireplumber is not active. Try the following commands to enable and restart it,
systemctl --user enable --now pipewire.socket pipewire-pulse.socket wireplumber.service
systemctl --user enable --now pipewire.service
systemctl restart --user pipewire-pulse.socket pipewire.socket wireplumber.service
If this does not help try reinstalling pipewire following this post
If neither of these work then check,
groups $USER
does not output audio or rtkit and that it does output realtime. In simple terms ensure you are a part of realtime group and that you are not a part of audio or rtkit groups.
Also check,
cat /etc/security/limits.d/99-realtime-privileges.conf
returns,
@realtime - rtprio 98
@realtime - memlock unlimited
@realtime - nice -11
Finally also try to change kernels if none helps,
sudo pacman -S linux-lts linux-lts-headers
and then from grub advanced menu select the lts kernel to boot into.