The 1/1 token also has a lot of practical applications, most of which I touched on with Rally the Hornburg, but most importantly, it puts something on the battlefield while you draw cards
If the target permanent is an illegal target by the time Feed the Swarm tries to resolve, the spell doesn't resolve
Then each player draws one card for each mana spent after your first, so small contributions will lead to everyone drawing a lot of cards
Having one early in the game can halt an aggressive deck's momentum
Palladia-Mors, the Ruiner I am sorry, fans of Arcades Sabboth, Vaevictis Asmadi, and Chromium
The Meathook Massacre is seeing solid inclusion in many black decks, especially from sacrifice-themed commanders like Teysa Karlov and Grismold, the Dreadsower