Right, but it can really cripple opponents with Knock Off and Will-O-Wisp. Due to its unique typing of Fire/Dark, it has good matchups into Kingambit, Gholdengo, up-and-coming Meowscarada and it's Icy counterpart Weavile, even Volcarona. Additionally, Deoxys-Speed and to a lesser extent Defense, even Draco droppers Latios and Dragapult fear Incineroar.
World Champ (Incineroar) (M) @ Heavy-Duty Boots
Ability: Intimidate
Tera Type: Water
EVs: 248 HP / 180 SpD / 80 Spe
Careful Nature
- Flare Blitz
- Knock Off
- Will-O-Wisp
- Parting Shot
This is not a good Kingambit answer. Let's say you're bringing in Incineroar after Kingambit shows up and it gets the free Swords Dance on prediction, giving it a net +1 Atk after Intimidate. Being generous, we'll say only two allies have fainted, so Supreme Overlord is giving only a 20% boost.
+1 252+ Atk Supreme Overlord 2 allies fainted Kingambit Low Kick (80 BP) vs. 248 HP / 0 Def Incineroar: 386-456 (98.2 - 116%) -- 87.5% chance to OHKO
0 Atk Incineroar Flare Blitz vs. 0 HP / 4 Def Kingambit: 248-294 (72.7 - 86.2%) -- guaranteed 2HKO
This is max speed Adamant, which outspeeds your Incinceroar by about 20 points. Max Speed Jolly Kingambit outspeeds this set by about 40 points, requiring Incineroar to reduce its bulk further to make up the difference or just pray it doesn't have Low Kick. Not being able to stand up to such a common set is kind of a problem.
It's also not that good at answering Volcarona either. The moth regularly invests in HP and Defense now, and Tera Blast Ground is one of the many options it can pull out.
0 Atk Incineroar Flare Blitz vs. 252 HP / 252+ Def Volcarona: 136-162 (36.3 - 43.3%) -- guaranteed 3HKO
As for the Draco droppers and basically everything else mentioned, they are not obligated to stay in against Incineroar and will gladly pivot out instead. Dragon and Dark types are everywhere right now and can eat either STAB, which turns Incineroar into a very mediocre Knock Off user. Great Tusk exists and will ruin its whole day before super-slow Incineroar gets a chance to Burn it. So on.
Also, if you want to use a bulky Fire type with a huge Attack stat and a secondary typing that provides additional defensive benefit, why are you not running Gouging Fire, who's faster, stronger, bulkier in HP and both defense stats, has a much better secondary typing, has options Incineroar doesn't like Morning Sun, and can even still inflict Burn?