In getting cards graded, their value and security are preserved, which helps collections or resale value
If you dont mind working a little harder to get its strategy to work (its a little trickier than the more vanilla Amber/Amethyst deck) then it will repay you in spades with a more powerful, thought out gameplay
The same is true for anything that would force players to draw from an empty library
Wrath of God gets a 45, while Day of Judgement - functionally the same in almost all cases - is all the way down at 18
Dialga EXs main attack, Heavy Impact , is sort of underwhelming for 4 Energy as it deals only 100 DMG, especially when Melmetal has the same attack but the latters ability, Hard Coat, makes it take 20 less damage from attacks