One of the reasons the now dead E3 transformed from an industry trade show into a 3 day pseudo-party of spectacle and mayhem was because it was the core source of funding for the Entertainment Software Association, the lobbying arm of the games industry.
Ironically, they tried to dial it back in the mid 2000s and turn it in to a more closed event due to some of the industry titans fearing the lack of control they have over bloggers that they have over more established press. However, at that point it became too materially important to their funding and since ramping up charges on key members of the group wasn't gonna fly, they were forced to dial it back and adapt to the internet era.
Anyway, this post isn't about E3 proper, this is more about the ESA it funded and why like E3 we had both a friend and foe relationship, and like E3 the "friend" part of the equation slowly withered away.