At the earlier stages that qualify you for the in-person tourneys, it's probably the players' hardware. Once you get to the later levels, it's in-person on Epic

At the earlier stages that qualify you for the in-person tourneys, it's probably the players' hardware. Once you get to the later levels, it's in-person on Epic-provided hardware. But there are tons of Fortnite players. Getting to the in-person rounds in and of itself could be worth it, as in the largest regions even the top 20-25 get more than it would cost to acquire a DMA interposer. So you'd have to be a top-level player who is cheating to gain an edge (which is probably the most common amongst all video game cheaters) as opposed to someone who cheats because they utterly suck. Then again, Epic is fierce when it comes to cheaters. They have taken multiple cheaters to court and won, once they got to the higher levels (or if they were involved in distributing/selling cheats).