"Goku has always been an Idiot" is a funny take when he's the only Z fighter able to put two brain cells together and come up with actual solutions to problems.
How to become even stronger with Super Saiyan? Master is so that it's energy consumption is too low, something Vegeta was too stupid to grasp. He's the only one to realize that Gohan was the only one capable of demolishing Cell at his full power. Him giving Cell the Senzu bean showcased his arrogance, not his stupidity. His "flaw" in that arc was not understanding his son on a fundamental level.
In the Buu arc he teaches the boys Fusion and is constantly making executive decisions because everyone else is either too incompetent, malicious or outright stupid to be of use (Good job reviving people who will inevitably killed again Yamcha, very smart). He has to hold back against his fight with Vegeta instead of going all out with Super Saiyan 3 because that form cuts into his time on Earth. He even decides to bribe Old Kai with sexy pics of Bulma and not his own wife, because by his own admission "Vegeta's wife is hotter than mine"
Z Goku = / Super Goku, no matter how much people try to spin it.
However, having actually watched Super... There's honestly merit to Super's approach to Goku. He's more "fun" and closer in spirit to what Akira Toriyama initially intended. Toriyama made Goku too pragmatic during the course of the original Dragon Ball run. And since Goku is dumber, it gives other characters a chance around him to shine, instead of uselessly following his orders like before.
I actually found the filler episodes to be pretty enjoyable because of him. Of course he's unforgivably stupid during parts of the Goku Black arc (where he comes across as infantile and incapable of taking things seriously) but for the most part he's actually kind of charming. And they struck an excellent balance during the tournament of power arc, finally hitting that sweetspot between endearingly stupid and serious when the situation calls for it
And in Super he
1. Figures out the way to find out how to become a Super Saiyan God by using the Dragon Balls to ask Shenron, if not Beerus would have blown up the Earth.
2. He, along with Vegeta, realized that they could actually hit a Super Saiyan level of the SSG form shortly after their use of divine energy
3. Learned how to beat Hit's time skip even in his base form.
4. Was able to use Kaioken while in his Super Saiyan Blue form even though he said he wasn't sure it'd work and would probably blow him up.
5. Used the Zeno button to save the timelines from Zamasu after he became an unstoppable force
6. Came up with the plan to have Frieza as the 10th fighter for ToP
7. Achieved full Ultra Instinct by the end of the ToP
Every single Arc in Super is resolved because of Goku in some way
Beerus - He enjoyed the fight with Goku s much where he pretended to fall asleep and spare Earth
Golden Frieza - With the help of Whis, he is able to kill Frieza before he blows up the Earth
Tournament of Destroyers - Changed Hit where he actually threw the fight with Monaka so that U7 could win
Zamasu - Summons Zeno to restart Trunks' timeline after it was ruined
Tournament of Power - He and Frieza knock Jiren out, and 17 is left standing. Both Frieza and 17 would have never joined if it weren't for him either.
While he is dumber and immature for comedy in the lighter moments, he is actually more clever than his Z self where it counts
I legit feel like I'm being gaslit when people say that Goku was the exact same in DBZ/Kai as he was in Super, but the English dub made me blind to it.
No. I watched Kai, subbed and dubbed, as an adult. Goku in that is great, and he's legit written to be more stupid and annoying in Super. If that's your thing, then that's your thing. But don't lie to me to support your tastes. Say you simply enjoy Goku not knowing how to count.
Goku's nature is the same, but he is different in each series. Just the same as most people are different in college from how they were in high school. You can't look at Goku on Namek fighting Frieza and then look at him after he has been through tons of other events and expect to see
You have to take into account that Goku in Super has the power of a god. Both he and Vegeta are guilty of not taking any threat seriously because of it. Frieza is back and more powerful than ever? Goku and Vegeta were arguing over who gets to fight him and be the one to defeat him. Beerus and Champa want a tournament where the Earth is on the line? Goku and Vegeta are sure they are going to have no trouble. Trunks says that an evil Goku is destroying his timeline? Hell even Trunks isn't worried when he sees SSB Vegeta. Tournament where only one universe survives? Vegeta is sure he will win and that he and Goku in their SSB form will mop the floor with the fighters there, so much that he thought Frieza being recruited was embarrassing for Goku.
Also, the dumbness is purely for the lighthearted comedy moments. You can find it irritating and feel it makes it hard to watch, but it is the sense of humor the show has and the style of comedy they feel fit. I'd see your point if Goku forgot who he was fighting or left in the middle of a fight to watch a puppet show, but he is very serious when fighting. Look at how he reacts to Zamasu and Goku Black when they tell him how they killed Chichi and Goten. Thats the same guy who didn't know what kissing was.
