For how much Garfield and Magics other core designers didnt yet understand about the future of the game, the reasoning for this was simple, and showed a tremendous amount of foresight: adding more and more cards to a single card pool would, in Garfields own words, collapse the game into complexity and would strongarm players into buying cards they might not want. Hmm
Maybe it betrays existence
Chandra, Flames Fury The problem with Planeswalker Deck Chandras (and PD planeswalkers in general) is how vanilla they are: Small amounts of damage get locked behind high mana costs
Once you have 5, it flips into Vault of Catlacan, a land that taps for any color or adds a blue mana for every artifact you control like the infamously banned land, Tolarian Academy
The rule box Pokmon for the current generation are called Pokmon V, mimicking the Dynamax mechanic from the Sword and Shield games