This is because as the number of players increases, the number of creatures on the battlefield generally increases too
Ambrosia Whiteheart Champion of the Clachan Dust Elemental Flock Impostor Jeskai Barricade Loyal Gryff Mischievous Pup Night Nurse, Healer of Heroes Otherworldly Escort Phelia, Exuberant Shepherd Rescuer Chwinga Restoration Angel Rhys, the Evermore Salvation Swan Samwise the Stouthearted Stonecloaker Sunpearl Kirin Vizier of Deferment Whitemane Lion
Both are fundamental in almost every aggressive deck that can use them and have a constant presence in various metagames in their respective games
At 4 mana, you could wipe the board of all creatures with toughness 3 or less, destroy three vital artifacts of an artifact-matters deck, or deal a massive 6 damage to each opponent
The only other exception in the deck list is Gimli of the Glittering CavesGimli of the Glittering Caves (27,572 decks), who also gives him double strike, but also the ability to make Treasure tokens when he hits