While it is usually more efficient to make the opponent draw a new hand with cards like Iono and Unfair Stamp to disrupt them, other cards care about the specific types of cards in the opponent's hand, and Whimsicott ex is one of these unique options
Here are some of the key staple cards in Pokmon TCG Pockets meta, with a little overview of what they do: Professors Research A Supporter card that lets you draw two cards, immediately increasing your card advantage and making your strategies more consistent
That said, there are some minor interactions to be aware of
Enchantments - 5
I would save the Wonder Hourglass for times when there are special picks avaliable and you need extra stamina to attempt them all
This is not a completely fair test, since the values we're listing here reflect the cards' prices right now, rather than the value they held upon release, but nonetheless it paints a pretty bleak picture