Sure, you have more cards to choose from if you go with more colours, but you also complicate your mana base
It can also be a formidable discard commander, and you can plan a discard-heavy strategy with it at the front
Red decks need their removal to be able to go directly to the face, which is the one thing you cannot Terminate, and while being cheap is nice, the creatures you need Terminate for don't come out fast enough to reward you much for it being so cheap
Clive #78 (Pokemon Paldean Fates | Pokemon Cards) prices are based on the historic sales
Deck building in Pokemon TCG Pocket often relies on the fastest and most effective ways to deal a large amount of damage
Thankfully, they added the number of lands you control clause so that Armageddon for nothing isnt one of the spells