Son's obsessed with Fortnite and I'm losing my mind

My 10 year old literally talks about nothing but Fortnite. He watches streamers on YouTube for hours, wants every skin, begs me to let him play during school nights. I know all the other kids are into it but this feels excessive. He got mad at me last week when I said no and actually yelled that I'm ruining his life. I feel like I'm fighting a losing battle here. Do I just let him get it out of his system or is this actually concerning?