Both these cards are old and won't be reprinted and while they're not needed in order to have a successful Shrine deck, having them will boost the power of the deck substantially
The Master Ball is guaranteed to capture any wild Pokmon (except for special circumstances where Pok Balls in general cannot be used), making it useful against Legendary, Mythical, or Shiny Pokmon
If you want to get technical, the role sits on the battlefield until the next time state-based actions are checked then goes to the graveyard since its not enchanting anything
Value, board presence, all while filling the yard for a game winning Season of Loss
Play Boosters are the ideal booster for the play environment - especially Limited format events
Laminated cards: Not recyclable through conventional methods