Valve is known for not forcing their employees to work crazy hours, but that might have hurt their ability to keep people playing. Less than a month after Artifact launched, everyone went on Christmas/New Years vacation, leaving a 3 week gap with no updates or communication from the devs. They lost over half the remaining players over those 3 weeks, partly because nobody was sure about the future of the game, causing a "prisoner's dilemma" with who was going to sell their card before the value tanked.