Outside of doubling or blinking ETB effects, we can look at some goblin payoffs, as there are a ton of goblins on this list
WotC owns the rights to the cards artwork , either through first printing rights (most likely) or full purchased rights (less likely)
(Artifacts, legendaries, and Sagas are historic.) The second mode of What Must Be Done cares about what the characteristics of the returned permanent will be when it's on the battlefield, taking into account static abilities that would change its types
That doesn't mean that milling is dead in the format actually, it's far from it
For an update discussion I recommend you to join the facebook group on magic counterfeit detection here
Due to this, the overall market for collectible MTG cards may have shifted a great deal since 2023 and earlier