Simultaneous Travel: Why Can't I Share My Power?

Before his time travel, Baishui often complained about proctology plug-ins while reading novels. Why could they share power even though the worlds were different? Sharing power would be fine, but why could everyone simultaneously unleash their full power? Wouldn't that multiply the total power? They could ignore distance and worlds, becoming stronger out of nothing, so why were they still restricted by the world, unable to surpass its limits? However, after his time travel, when he discovered that his plug-in couldn't share power, he just wanted to give his pre-time travel self a hard slap in the face, scolding him for overthinking it and now causing his plug-in to be downgraded. Then he was happy.