Idk how much you know but I think this is supposed to be like league so it's a 5v5 game where each team has one person for each role. If you say something like "jungle diff" typically it's because you're implying that the other team lost because the difference in skill between the two people in those roles was so massive that it cost them the game, basically saying they suck
Taeyoung says it to Jihan as banter since they are close friends and unfortunately Yoojeong is too socially inept to realize the distinction so he kind of just clowns on Jihan like crazy and then tells him he's trash unprompted

Guys I read the chapter and I saw his comment
But like I don’t game as much can someone please tell me what he said?
How is that a misunderstanding or rage bait?