Hello, I am not really a great Showdpwn player but I would like to voice my opinion about sth. I am sorry about the long post
I have seen some people say Gouging Fire needs his attack protoboost to reach his full potential but I very much disagree. Sun teams have always been my favorite playstyle ever since it debuted with Ninetales since fire types are favorite types ever. So I extensively tried to built many different sun teams, stole some sun teams I have seen on the ladder or rmt and experimented with them. And yeah Banded GF with speed boost is easily the best set so far. This is also a mon that is always worth it to tera fire to reach absurd number even with speed boosting ones
Set-up GF is kind of a waste in sun. It is way to slow momentum wise + you will need multiple boosts to outpace some offensive mons like other Valiant or Deo which just doesn't make it worth it( your sun turns are limited so you have to get a lot of value with every turn. I will say though, it is slightly better against protect stalling mons like water Gliscor but other then that CB is much better here since weather in general is about maximizing your turns. Outside sun , bulky setup is better due to having multiple opportunities to come(thanks to morning sun) and having a suprisingly good defensive typing that checks dangerous mons like Volc,Ghold or Gambit(outside tera). .
Speed boosting Scarf is funny. It does well against HO teams(can even suprise kill a speed Moon) but does worse the bulkier the team gets.
CB Attack boost hits like a nuke but it doesn't do as well against teams with focus on offense. They don't care if you can nuke a mon after all, they care more about mons outspeeding them and GF speed is kinda eh. And that is where CB speed boosting Gouging Fire comes in. With a choice band and the sun up, he basically starts with a +2 attack and +1 speed just by entering. Isn't that much better then having a +2,3 attack boost?
By adding speed, popular offensive checks to GF become fodder instead. Dragapult? Will become an actual ghost and pass on to the next world. Roaring Moon? What a beautiful grave that shines under the moon. Zamazenta? Gets 2HKO instead of 1HKO'd but you would have to take the hit anyway or deal with ID shit. There are other like Enarm, boosterless Treads or other setup mons at +1 that become an issue once GF is chipped if he were attack booster but are not an issue for speed boosters.
I will say, though, the attack boosting CB Tera Fire adamant GF does insane shit like OHKOing Ting-Lu and 2HKOing Dozo but being outsped by so many offensive threats is just not worth it. 3HKOing Dozo and 2HKO Lu is still good. Being forced to rest and getting chipped is basically a death sentence for Dozo especially if you have teammates that can pressure him. Here is one example:
https://replay.pokemonshowdown.com/gen9ou-2057041095-j58cb7tdkwwb4lj0r2gf1n2ihnpx3t7pw
This example here has many things that GF hates(a tera grass flash fire mon, Tyranitar, Iron valiant and Garchomp that gives free chip to you). Still managed to clean up afterall(although I dont like how I played against Ceruledge)
https://replay.pokemonshowdown.com/gen9ou-2057051586-rz2wvrwhmz0qnpkgmaehvvg6289lg65pw
And here is an example of GF vs an average OU team
https://replay.pokemonshowdown.com/gen9ou-2055562914-bb0mte8s9wtm2yvwqw1na71ygs7ykuupw
Here is another irrelevant example for people who hate rain
https://replay.pokemonshowdown.com/gen9ou-2056432270-l8aryswp5rpubg8m4j9np85dzumyuqmpw
Tl:dr: Speed Gouging Fire is one of the most oppressive mons in the tier right now. Not sure how much the tier can handle after rain falls off but I am having so much fun with this mon. You just get sun up, bring him in and mindlessly click a button. In fact NOT playing stupid is actually a hindrance since the opponent can counter offense you. Which is why I love this mon. Don't think I have felt this way since Chi-Yu. I still miss my CB Victini though.