It was so dominant that people even played Jace Beleren, the cheaper 3-mana Jace, partly as a weird answer to it, because the planeswalker legend rule at the time let you drop your own Jace and immediately get rid of your opponents
It has been eighteen years since Betrayers, and the number of cards that ignore the legend rule in some shape, form, or fashion has increased, with many of them being released in the past two years, in Modern Horizons 2, Kamigawa: Neon Dynasty, Strixhaven: School of Mages, Commander Legends: Battle for Baldurs Gate, The Lord of the Rings: Tales of Middle-earth, Wilds of Eldraine, Commander Masters, and Doctor Who Commander
Thats already a lot harder to get, as each of the other mythics are at most 187 packs
Plus, its a 12/12 with annihilator that can force opponents to sacrifice permanents and get the engine running
On HULK SMASH!, you'll be able to choose both modes, SMASHing with reckless abandon