You may have up to four Steelix and one Radiant Steelix, for example, but no more Radiant Steelix cards even if you got rid of regular Steelix cards
Survival is mostly found on white and green cards, signifying those colors struggling in such an oppressively evil environment
Wearing gloves can leave marks on the cards, and this can cause players to put a lot of pressure on the cards
Skarmory EX can form a powerful Metal deck with the infamous Solgaleo EX
Not only is the Power Nine mostly artifacts, but some of the most broken cards I can think of are artifacts: Skullclamp, Umezawa's Jitte, and Smuggler's Copter all demonstrate the power of the card type before I even scratch the surface of fast mana like Mana Crypt and Sol Ring
Its especially useful in slower games, where you need to keep drawing gas for your board