PSA: that $20 under-desk cable tray was the best money in my whole setup
I fought the rat's nest behind my TV and console shelf for two years before I finally bolted a cheap metal tray under the desk. Twenty bucks at the hardware store, four screws, and every power brick and HDMI run sits in it now. My cat used to bat the loose cords around at 2am and that stopped the same night. If your closet setup looks like a spider died back there, what's the one cheap thing that actually worked for you?
Wait, hold on... twenty bucks was the best money in your WHOLE setup? That tray is doing real work, sure, but best money? No way. The thing that actually fixed your setup was you finally getting off your butt and bolting it in, the tray was just the tool. You could've had that tray sitting in a bag for another two years and the cords would still be a mess. Also, a metal tray is only half the answer, because if you don't leave some slack in those cables you're gonna yank a plug loose every time you roll your chair back. And power bricks stacked in a metal box can get warm, so check it after a few hours of the TV running, mine got toasty at first. Still a solid move though, and the cat thing alone probably saved you a fire scare.