They are brilliant in that they are an easy way to avoid having to use a Trainer for something while also providing an Energy
It's skipping its turn
I could keep it at 45, and either run a copy of something like Mezuki, or run 2 Co-Forbidden cards which would likely be of either Psy-Framelord Omega, Card Destruction, Dark Hole, Pot of Extravagance, or one of the Solemns
If I play three creatures, and then you kill them all with a Wrath of God, you've got card advantage: You used a single card to get rid of three of mine
The SIR format gives the illustration a tactile quality that elevates it above a standard card, and the combination of the shiny Pokemon theme with the SIR treatment creates a premium product that appeals to collectors who value both rarity and artistic quality
While these cards used to struggle in a meta that was too fast for them to keep up, they can now efficiently respond to a slower format with powerful attackers like Iron Hands ex and Miraidon