The main reason it's relegated to the number two spot is the number of dice
The two work best when together, of course, but there are also tons of new artifact creatures that care about energy, both in the Fallout precon and throughout Modern Horizons 3 , and even a little bit back in Kaladesh
getting a bunch of bodies in one card works in many strategies, including tokens, aristocrats, and, of course spiders
Copter is a 2/3 flier for two rather than a 1/4 flier for 2 when compared to the Heart in this crude goldfish analysis manner
The Scion is very powerful and Spike-y at the kitchen table and should find a big following in Commander and I wouldn't be surprised if it winds up with north of 1,000 decks registered over at EDHREC.com
Evasion Evasion refers to abilities on creatures that make them hard or impossible to block