Most other mass removal spells in Standard right now either cost more mana, have some sort of stipulation on them that gives your opponent something in exchange for blowing up the board or just isnt as efficient as Day of Judgement
If you do mill someone out, youll statistically be laughing anyway, because its the most evil and also the most entertaining way to win a game of MTG
The extra bonuses granted by 20 and 40 toughness are just gravy, and you can try to accomplish that if youre building around this card
Youll have to play most of the 24 mutate cards available in the Sultai wedge to do it, but there are a few stars, many of them on the above list
It certainly leans more towards a Pillowfort or control strategy, but you can also leverage its power through politics
It has a powerful effect for Commander, and that also makes it worth more