You could use the Cauldron to set up a slow loop of sacrificing and reanimating two creatures with powerful enters abilities or just turn a random pest into an Archon of Cruelty, whichever suits you in the moment
Like Transgress it has always been a backup option when the better spells are gone but there really isn't that much redundancy in "targetted" one mana discard
Between reprints, Commander sets, Universes Beyond, Secret Lairs, and more, Magics total number of cards has ballooned over the years
Riley Standard Not Legal Alchemy Not Legal Pioneer Not Legal Historic Legal Modern Not Legal Brawl Legal Legacy Not Legal Comp
Plus, nothing can gain flying later with effects and such, so you are confident that your team will be unblockable again and again, turn after turn