TV’s lavish Upfronts once featured booze-fueled nights, execs in light-up dresses, Kanye West performing in a pyramid and Miley Cyrus smoking weed onstage. But as the annual event kicks off next week, the streamers now dominate all the over-the-top party spots while network execs are largely left wondering what they’re even doing there — as they scrap for their dwindling pieces of what’s still a $30 billion pie.