Many are optional, but some are mandatory, or even negative for their controller
Many, many characters in this deck are pirates - 24 different characters show up in this deck, of which 17 are pirates - and through various benefits and mechanics, the deck is telling you that it wants you to swing away with them and whittle down your opponents to get an upper hand on the board state
Neither deck was suitable to play in a world where not only there would be non-Eldrazi decks but people could rationally choose to play decks like U/R Eldrazi
In two or three years, I wouldnt be shocked if the Gods start climbing ferociously in value, especially if Magic keeps growing
Strong Magnetic Lid: Forget complicated closures
Witherbloom Pestilence is a grinding, aristocrats style deck with life gain and +1/+1 counter subthemes