Why was the timing of comet water delivery advantageous after the initial violent stages?

Answer

It provided a sustained infusion when surface conditions favored the stability of liquid water pools

The continued arrival of comets provided a sustained, relatively mild infusion of water when the Earth had cooled enough for liquid water to remain stable rather than being boiled off by intense heat.

Why was the timing of comet water delivery advantageous after the initial violent stages?
OriginEarthwatercometlife