

While the game can be “addicting”, it is mostly because it is fun to play. Not all “addicting” forms of entertainment need elevated ratings because they are fun to consume. We don’t increase the ratings for binge worthy TV shows and we don’t restrict books if they are page turners, so why should we with a video game. At some point people need to regulate the use of their time themselves.
The “willingly” makes the difference there. That changes it from negligence to intentional, and those are legally distinct.
If Amazon, or another marketplace, isn’t aware of the danger of a product sold by a vendor on their platform, it’s not clear if Amazon, or the market provider, is responsible. Amazon is arguing that they aren’t, but I don’t know enough of the law to say if that is a settled question.