Streaming ate into physical media because it was more convenient and people didn't care enough of the quality of the 'stream' from the physical version over the convenience of the streaming services.Streaming killed physical media but that's because you just sit there and watch or listen to movies and music.
I am not arguing that hardcore gamers (aka people spending 400 USD+ per year) will get converted, same like I don't think people buying UHD blu-rays will convert to streaming all of their movies. There might be a minor % of their time but I think there probably will have to be a different audience that buys into streaming services.Gaming is interactive and no one can solve the problem of Internet lag which ruins the interactive aspect of gaming in fundamental ways. Since it's not possible to exceed the speed of light with our current level of technology, cloud gaming will always be limited to very casual games. Unfortunately, mobile controls the casual games market.
Again I just find definitions around casual and hardcore a nebulous one if we don't define it more precisely.