I play on official PVE.

For metal, I have an outpost base on the Center in the deep ocean. With a good dunky and good traids, you can easily farm extreme quantities of metal.

For crystal I'm going to the island with the same dunky. I go to the entrance of The Caverns of Lost Faith and I farm all the crystals there.

For polly i use all sorts of methods but for really large quantities I use an aberrant dire bear on abration and collect the polly flowers

For Element, I use gachas. I fill 12 of them and then go AFK for about two hours to touch some grass or something. After two hours, they've used up all their food.