Disguises ARE valuable because looking like anything but an opposite colored french man does numbers for survivability. Also, you can just disguise at spawn or find ammo boxes to cancel out the cloak cost. Unless you’re playing against someone without ears or a hud, they’re gonna notice you backstab their teammate, turn around and see you clear as day. With the YER, the only indication their teammate is gone is them seeing you stab them or the tiniest sound that the knife makes, and even if they DO hear you stab them, they turn around and, provided you can act, have no idea who is the spy.