For 4 mana, it wipes every creature off the battlefield and even stops regeneration, which made it the clean benchmark for sweepers for a long time
The hideaway cost is a nice addition, but even if it didn't have it the card would still be amazing
Typically, token strategies fall apart because the opponent can present blockers that will cost you tokens when you go to attacks
You can also use it to generate additional storm count and even mana by bouncing your own stuff and taking advantage of making copies, lands be damned
But with so many fans of both Magic and Lord of the Rings, the value of these particular cards seems to have some staying power
Entreat the Angels, Starnheim Unleashed, Finale of Glory, and Decree of Justice all reward you handsomely for spending a lot of mana on them