Overworld-only portal gold farm

An overworld gold farm built out of oversized nether portals. Every portal block has a small chance on each random tick to spawn a zombified piglin on the overworld side, so the design stacks huge portals until that trickle becomes a stream, then drops the piglins into a manual kill spot. It is modular, each extra layer of portals adds about 200 gold blocks an hour. Java, no nether roof needed, but the obsidian bill is enormous and it only runs while a player is standing there.

The piglins that spawn from the portals count toward the hostile mob cap but are not limited by it, so a mob switch costs you nothing and helps a lot while you are placing the portals.
Since spears were added the piglins can reach the AFK spot through the gap. One builder moved the kill position down to the piglins feet with a trapdoor in the middle and a two layer snow pedestal to stand on, another suggests a closed trapdoor and an armor stand hit with sweeping edge.
On Hard you lose hunger from every hit and can starve while AFK. A full regeneration 2 beacon replaces the chicken cooker and makes the spot safe without eating.
On 26.2 baby piglins are smaller and slip through. Put a glass block on top of the water flow on the right side of the killing chamber.
Light the portals from the very top and let the piglins fall the whole way down onto water above the trapdoor. Much easier than the method in the video.
The farm cannot be chunkloaded. Random ticks only run near a player, so no vanilla chunkloader will automate it.