Just the fact that you can play quality games in the cloud (without a gaming PC) and without paying for the games, just the Prime subscription, which gives you access to free Amazon deliveries for those who buy a lot, access to Prime Video for those who like some series and movies. The cost-benefit is great.
Meanwhile, on GeForce Now, you need to pay your monthly subscription and pay for each game you want to play. It’s not worth it. Sure, in the end the game is yours, it stays in your library forever, but I don’t know.