I feel there isn't really any replacement though. CES maybe but kinda loses that dedicated feeling.
How do those passes work btw? I used to newspost on a now defunct competition site and the only time that was talked about was after I attended a Naughty Dog talk, but was after the fact so I never attended anything with a media badge.
There are three different "parts" to E3: the press conferences, the show floor, and the meetings. The badge you apply for needs you to be a reporter in some capacity, and the site needs to have a certain minimum threshold of MUV. That badge you get from that will let you onto the show floor, aka where all the booths are to play the games. In the old days, you could get around pretty easy, because there were a lot of people, but it wasn't impossibly congested to queue for demos. After they opened it to the public, it was like trying to get on a Disneyland ride in peak summer. They'd have company reps waving signs saying "YAKUZA DEMO WAIT TIMEl 4 HOURS!"
The second part is all the meetings. These take place either in rooms off the main floor, at restaurants across the street from E3 entirely, or on the show floor, but in a special line. When I got invited to Nintendo's booth for media, it was just where a bunch of people were chilling out, passing out snacks, and getting exclusive hands on time with the big games--BOTW, Odyssey, Smash, etc. I remember Charles Martinet and Miyamoto just milling about, and being sorta shocked that I was mere steps away from them. I wish I would have had the guts to ask for an autograph. All those meetings require a LOT of finessing though, like having good contacts with PR, chasing after interview slots, stuff like that. But that's the best part of E3, hands down. You don't just get given those, though, unless you're like, IGN I guess.
Then there's the press conferences, which are the big showcases--really the only thing of E3 that the public sees? Those, too, are really hard to get into, and are basically fancy lounges where they serve alcohol and meals. I know I wasn't allowed to attend Sony's showcase because there was so much alcohol involved, and I was <21 at the time. They're basically gigantic movie theaters, and you get to see the Direct/Showcase about 10 minutes earlier than Twitch/Youtube because of stream delay. I know some of the things I updated in the live news docs were ahead of the broadcasts online, back when I went to Bethesda's.
Having JUST a media badge, even at the peak of E3, really didn't do much. And obviously no one is around to explain any of it, you kinda gotta wing it and learn by mistakes. It's all about who you know, making connections, and getting your way to the exclusive stuff.