Spear looting gold farm

A single dimension gold farm on the nether roof that kills with spears instead of with you. Zombified piglins spawn on magma platforms, turtle eggs walk them into a drop tower, and four zombies holding Looting III spears, kept swinging by an iron golem behind soul sand, hit them in mid air right at the edge of the despawn sphere. Looting applies without you touching anything and crafters turn the output into gold blocks. About 550 gold blocks an hour, fully AFK, no portal linking, no autoclicker and no spawnproofing. It gives no XP, since nothing here is killed by a player.

The AFK spot is exact and the video never says why. It puts the edge of the despawn sphere at the leaf block, so the piglins despawn and die on the spears in mid air. Stand too close and they stack up on the leaves alive.
If the zombies never raise their spears, the sightline to the iron golem through the soul sand is wrong. Check the trapdoor and the repeater they stand on, the angle is very specific.
Keep the scaffolding away from the farm. Too close and piglins get stuck at the bottom and die to entity cramming instead of the spears, which loses the looting and most of the rate.
Baby piglins are not attacked. They grow up inside the kill chamber, take up space and cost about 40 percent of the rate on 26.1.2 and later. Nobody in the thread has a fix.
The switch that powers the activator rail must not power any other rail, or the zombie never gets out of the minecart.
Some piglins die from the fall before a spear reaches them. Another powder snow block before the second drop, near the dripstone and the repeating pistons, softens it enough for the looting to still apply.