They wanted to create a game that both kids and adults could enjoy
Sproutback Trudge Sproutback Trudge is a huge 9/7 trample creature card, and it becomes cheaper to cast the more life you gain in a turn
But there, again, it is not Ephemerate itself that makes the deck good and consistent

Aatchik, Emerald Radian Aberrant Researcher Acridian Adaptive Shimmerer Agitator Ant Altanak, the Thrice-Called Ambush Gigapede Ambush Krotiq Amzu, Swarm's Hunger Ant Queen Ant-Man's Air Force Ant-Man's Army Anthropede Arcbound Stinger Army Ants Atraxa's Skitterfang Bane of the Living Barbed Shocker Battlefly Swarm Baxter, Fly in the Ointment Bayou Dragonfly Beetleform Mage Bilious Skulldweller Biomechan Engineer Biotech Specialist Blade of the Swarm Blightbeetle Blister Beetle Bloatfly Swarm Bond Beetle Brain Maggot Brain Weevil Brass Gnat Brood of Cockroaches Broodguard Elite Broodhatch Nantuko Buzz Bots Buzzard-Wasp Colony Canoptek Scarab Swarm Canoptek Tomb Sentinel Carrion Ants Carrion Beetles Carrion Grub Carrion Locust Caustic Caterpillar Caustic Crawler Caustic Wasps Cavern Crawler Chainflail Centipede Chillerpillar Chitin Gravestalker Circuit Mender Clickslither Clockwork Beetle Clockwork Swarm Coiling Woodworm Colossapede Comet Crawler Crash of Rhino Beetles Cuboid Colony Deadbridge Goliath Deadly Grub Deadly Insect Decimator Beetle Delta Bloodflies Devouring Swarm Dimir Spybug Distended Mindbender Docent of Perfection Dragonfly Swarm Dross Hopper Drudge Beetle

I suspect this will happen more often than you might imagine
I criticized the Madrigal deck for only having one win condition in 004-018, this one has more agency in that regard