E3 gets guaranteed coverage in all major newspapers and the Beeb here with tentpole games mentioned by name. That is worth spending money for. Conferences don't have the relative impact they used to but there's no need for hyperbole.
There's no hyperbole and videogames aren't unique. Industry trade shows are going away almost across the board in all major industries. They hit a height in the 1990s and early/mid 2000s, and since then, consumers and industry journalists don't need tradeshows to see products.
It starts with the big players. Apple and Google don't present their big products at CES because a big tradeshow hurts them. Likewise, Rockstar, Nintendo, Valve, and other heralded gaming brands usually don't present their big products at E3, or GamesCom, or the others, because it hurts them to present there, where they can have their own video reveal at their own time, and control the entire news cycle for a day.
Also, there's very little value for the industry in getting newspaper coverage today. Spending hundreds of thousands of dollars, or millions for big publishers, on tradeshow appearances just for newspapers to cover a game results in almost no purchases, where as spending virtually nothing on a Twitch livestream or YouTube/Hangout Q&A results in a lot more views and a lot more potential purchases. A single email blast from Rockstar games has a direct reach that is magnitudes larger than the largest newspaper coverage in the country.
Gaming doesn't exist in a vacuum here. CES is garbage today because the companies making products you want have a small or non-existent footprint there. Instead of seeing the newest Apple MacBook or Microsoft Surface, instead you see App-controlled lightbulbs and new 3rd party charging adapters, or a new toaster oven that you can control with your Turtle Bay app. Even companies that are small and getting off the ground don't have big presences at tradehows... Tesla is one of the hottest brands bridging consumer electronics, automotive, and home automation devices, and yet, they don't have significant presence at either CES, the Detroit Auto Show, or the National Home Show, the three largest tradeshows in those industries. They don't need it.
I don't think E3 is going away tomorrow or next year or in 5 years, but it's going to follow the trend of all major industry trade shows.