Never heared of the site, but judging by the given creation dates, it only launched last year?
Mission seems to be game archival and there is indeed a lot of stuff that likely no copyright holders care about anymore. And that is likely of value for computer historians.
But in addition to that, it is also used to share modern, non-game media. One folder contains 10 different Alien (the movie franchise), two Finding Dory Blu-rays (as ~40GB zips), plus a few dozen more... I'm pretty sure stuff (piracy) like that also increases storage and bandwidth costs, while they don't align with the stated mission. And I think that stuff is unlikely to go missing any time soon; in fact Jeff Bezos will be happy to ship you a copy.
I don't want to deep link, but the article mentions the site's name. The folder is "files/No-Intro/BD-Video/". There is more like that.
