That way beasts can get better without busting Standard
Double attack triggers for 2 mana is pretty spicy, even if it takes time to build up
This is where Sol Ring shines as the king of Commander
The early-game removal (Conclave Tribunal and Pacifism), combined with a number of powerful life-gain effects, will allow you to make it to the mid- and late-game when you can cast any one of your 13 strong Angel creatures (including 6 rare and 5 mythic creatures!) Once you cast these powerful flyers, you will be unstoppable
If you are in the energy deck, however, then this is just a threat that has to be removed, preferably on the stack, before you make 10 beefy Robots that will define combat for the rest of the probably very short game
There is of course a special serialized card for The One Ring, printed in the Black Speech of Mordor and unites the rest of the poem with the rest of the Sol Rings