The job of Wizards of the Coast is to make cards fun and hard to evaluate. What I mean by “hard to evaluate” is that if two cards cost the same but one is 2/2 creature and the other one is a 3/3 creature, the 2nd card is always superior. Suspend is a good mechanic because it makes cards hard to evaluate. Should I pay G now or 4G later? Suspend also creates tension, because your opponent sees any suspended cards.
We all know Akroma, Angel of Wrath is a great card, but when Legions first came out paying 5WWW seemed like too much. Tooth and Nail doesn’t work with basic lands, but is a standout with Urza's lands. It has been said that there are no good cards, only good decks, which is true. A card isn’t good in the abstract; it is only good if everything in the whole deck works together. Wrath of God doesn’t fit into every white deck just because it is a good card. Wrath works great in a white control deck, but definitely not in an aggressive beatdown deck.