2 mode gold farm

A gold and XP farm on the nether roof, the biggest one in common use. Zombified piglins spawn on stacked magma platforms, turtle eggs walk them into drop tubes, and a kill chamber at the bottom either finishes them automatically or lets you do it by hand for the XP. A honey block toggle switches between the two modes. It claims 600 gold blocks and 90,000 items an hour, and it ships with its own sorting system because ordinary hoppers cannot keep up with that. Java only, a full day of work, and the rate lives or dies on spawnproofing.

mobGriefing has to be true or the piglins cannot pathfind to the turtle eggs and the whole farm just stands there. This is the single most repeated warning in the thread.
Remove the redstone block under the note block once the build is done. Since 1.18 the item pusher jams with it in place, and builders on every version from 1.18 to 1.21.5 report the same fix.
Spawnproofing the despawn sphere is where the rate comes from. One builder measured his output jumping eight times over after doing it. If you cannot face it, set render distance to 2 chunks, which gets you most of the way.
Since 1.21.11 piglins spawn with spears and can hit you in the manual kill spot. Replace the top three trapdoors in front of you with glass and the bottom three with top slabs, put an armor stand on the middle ender chest, and stand a block lower so you swing past them. Keep knockback and fire aspect off your sword or you break the armor stand.
Replace the bottom glass of the kill chamber, above the melon, with obsidian. Otherwise manual killing breaks it constantly, especially with an autoclicker.
The 33 melon blocks can be anything honey will not pull. Pumpkins, furnaces and obsidian all work.