Because the Switch Lite doesn't dock to a TV, AFAIK there is no reason why it cannot have G-Sync, everything it needs is already built in. (There's no way they're using the original big proprietary, power hungry and expensive G-Sync module, they're almost certainly using "Mobile G-Sync", more on that here https://www.anandtech.com/show/9303/nvidia-launches-mobile-gsync ). Apparently Mobile G-Sync could also improve the battery life a bit, which is important to Nintendo. Mobile G-Sync wouldn't increase the cost at all, I just can't think of a reason why the Switch Lite wouldn't have Mobile G-Sync.