Why is Genshin not free?

I understand that Genshin Impact has gained immense popularity in recent times, and many players have been enjoying the immersive gameplay experience it offers. However, I must ask, why is Genshin Impact not a free-to-play game? As a fan of the game and the wider gaming industry, I'm curious about the decision-making process behind making Genshin a paid game. Are there specific factors or reasons that led the developers to choose this monetization model? I'm eager to learn more about the rationale behind this decision.