Most of the cards in this deck are included for their keywords, not for random value
It was always a special experience to open a booster pack and hunt for the rare and valuable cards
For just one mana, it essentially doubles your chances of a good roll on all future dice effects
(2: Target creature gets +X/-X until end of turn, where X is the number of artifacts you control.) It can help you destroy a specific creature or boost one of yours, but you have no control on what X is unless you keep artifacts in your hand that you can play to get the correct X you need
Ashnods Altar, meanwhile, gives you mana
The copies created by Feather, Radiant Arbiter's last ability are created on the stack, so they're not cast