Minecraft wiki entry for Zombified_piglin_farming, associated text: The crowding damage will let the farm run unattended as long as a player is close enough to keep the mobs from despawning, producing a stream of gold nuggets and rotten flesh.
Alternatively, you can take your Looting III sword and kill the ZPs manually, for about three times the gold and some grindstone experience.
Or, the two can be combined: Wield the Looting sword, but don't use it (much). Let the ZPs accumulate in the catcher, but occasionally punch one of them to aggro the group, then immediately go back to the Looting sword. Once the crushing damage sets in, their deaths will be considered your kills, yielding experience and the more generous gold drops. The catch here is that you need to stay mostly in front of the ZPs, to maintain the aggro -- if you move out of line-of-sight, their forgiveness timer starts ticking and they will eventually calm down.