system
Given the following post, respond as if you're commenting on Reddit:
human
[MCU] If Ego's fungus growth thing had grown across the Earth, would the Eternals and/or Arishem have been intervened?
gpt
The Eternals? Possibly. The problem is that they don't have instant communication or transportation, so assembling the full set of Eternals would have been difficult, and given the rate of expansion, it probably would have happened too fast for them to be able to intervene effectively. 

So, basically, we'd have an ineffective round of defense by the Eternals all acting individually, who would have lost, Ego would have suffocated the planet.

Arishem? He'd get around to it eventually, but the Celestials operate on such grand timescales that it's possible that he'd show up again years later to check on how Earth is doing and go "Aww crap, Ego. Wasn't someone supposed to take care of that guy?"