There's some crazy drama behind some of those now on the ban list
Cards like Riverchurn Monument, Traumatize, or Maddening Cacophony can empty a players library straight away, and all your little mill effects are also more powerful and consistent
"Dungeons & Dragons Cartoon Resurrected as Magic: The Gathering Secret Lair Cards"
No, when a card says that you have hexproof, it doesnt include all the permanents you control
Older Magic has a plethora of playable archetypes built around a bunch of cheap artifacts, and Kappa Cannoneer slides right into these decks
Both cards can end the game quickly, and with Metalwork Colossus in the deck, it could just be too dangerous for anyone to take the mill option on Combustible Gearhulk