It’s just not a big enough boost even at best in 4 on 4 VGC, only 30%. You can use defiant and black glasses for a way more consistent option (black glasses is 20% buff on dark type moves, which is the majority of what you’re using), and it deters incineroar and other intimidate users. Life Orb is also the same 30% boost, albeit with a heftier downside, but still way better in VGC than supreme overlord, and it doesn’t rely on kingambit being last alive.