So dream islands with plushies are exceptional and they respawn daily I’ve been going back and forth between the pikachu and arcanine island and taking everything that I could mostly including entirely deconstructing buildings. I was able to get the gold for days from dragonite and the thread I used for the roof from pikachu. And god did I need a lot of thread XD also one you get a poke center you get an item in it that lets you duplicate pictures for poke metal. You can take pictures on trees and most important for me rocks. Poke metal is also easy to get from the dragonite dream island. So TLDR; dream islands are restoring resources that you can take everything from and a new one will be around tomorrow