With my group, we have at times had 2 campaigns running in parallel (with different GMs). Each with different parts of the same core group.
As the only member of the group with full time job and wife and kids, sadly I missed out on some good games. But the rest of my life wasn't stopping the others from being able to achieve "quorum" (We've generally said we go ahead as long as only one player is missing.

It may well have helped that the different games run have always been different systems - different settings, different styles