I'm sure I am in the minority, but I found a division sigil in a dungeon. I activated it and use a cursed earth farm. I use diamond spikes/fans/conveyer belts. I also use the witch water bucket from the witch killing quest to turn skeletons into wither skeletons. I don't get wither skulls, but I do get necrotic bones and red hearts, so I could fill out my red heart canisters. I have some conduits with a filter/trash can to save what I currently need because there are SO many drops I can't keep it all. I also have a poor villager that I cured, tucked away underground next to the diamond spike, to lure the zombies over without effort.
I have had a few downsides to my design, the most annoying one being that every few days (real time, i run a server on my computer when I'm not recording to keep the farm going + my ender pearl farm going, let meteors fall for resources) something will blow a hole in the wall. I think it has something to do with support creepers/some infernal variant. TBH I've just been disabling mob griefing when I run it in the background because it's not worth the headache. The only other real problem I have had is that Skeleton Majors (the big ones) sometimes get outside of the farm, but they still just stand there trying to get to the villager. I think that they try to get on another mob (a la Jocky-style) and they glitch outside the wall. A couple shots from my crossbow and they are dead, but it is a nuisance. I've filled a few barrels of liquid xp for myself/my blacksmith's assistants. I have shown it off in one of my videos before, but sadly I don't remember which one it was.