Outside of the fact it has a good chunk of firepower on its own but by combining other strategies, its become an unstoppable powerhouse
When an opponent's monster declares an attack: You can activate this effect
A Set Booster has 12 playable cards (plus an art card and a token card)
In addition, while their opponent controls any Fusion, Synchro, XYZ, or Ritual monster, the player can Special Summon it from their Graveyard, albeit without its burn effect
Youre far better off visiting your local independent store, or buying graded cards from trusted online marketplaces, so you can be sure youre spending your money on the card you really want.
Yet, in terms of win rate and favored matchups, its performance has been fairly average