I would like to automute certain audio clients when I want, without human intervention (e.g. pulling up pavucontrol) when using Fedora/pulsewire. This worked before using pacmd, but that doesn't work under pipewire; and the replacement command, pw-cli, doesn't support set-sink-input-mute or set-source-output-mute.
pw-cli doesn't seem to support muting that I could see. pw-mon shows a relevant change when using pavucontrol (or easyeffects) to mute a stream, but that didn't help me figure out how to do it myself.
This is a bit late but i recently needed it too. Instead of pacmd you can use
pactl set-sink-input-volume <sink-id> <volume>