Today, the video games industry has much different means of marketing and communications than we did in 1995. Perhaps YouTube streaming is the new E3?
[1] https://archive.org/details/GamePro_Issue_056_March_1994/pag...
Traditionally E3 was about developers showcasing games for the press. But that's always been a bit of a tough sell for a major event, and I'm not surprised it's struggling given the current media landscape.
PAX is better at managing a public event. E3 wasn't originally open to the public, and once they opened up it was never done very well. If publishers want to have that public convention thing, PAX is better. Letting the public in to E3 sort of ruined the industry insider aspect of the convention, all the meetings moved to hotel rooms so that people could hear each other.