"Code Geass makes other characters dumber to make Lelouch look smart" is one of the most unfair criticism I have seen Code Geass get

Now, Code Geass is a flawed show and I accept it despite having a lelouch glazing username and had a lelouch pfp for a long time. But one criticism that I find is completely unfair is..."Side cast is made to look stupid so that Lelouch can appear as a genius which is far far from true."

First of all, Lloyd, Rakshata and Nina are geniuses in their own regard. They are scientific geniuses(Nina is a scientific prodigy who created the FLEIJA and anti FLEIJA), Lloyd(alongside Cecile made Lancelot and constantly improved it) and Rakshata(Guren and a scientific rival to Lloyd). They are far from stupid but am not considering them solely cuz they aren't the brightest in diploma and strategy/tactics.

Diethard is extremely competent and smart individual who managed to deduce Zero's identity of being britannian way earlier than his contemporaries. There are many moments where he is pragmatic and his advices are hardly dumb. He adviced BK to back off when they were on a clear disadvantage against Xing Ke when other members wanted to save Kallen. He also handled the whole VIletta/Ohgi stuff pretty cunningly given that there was a high chance that Viletta could have killed Ohgi if it wasn't for Sayoko to enter, who was sent to tail ohgi by Diethard.

Then, VIletta was competent in her own regard too. She was able to deduce the identity of Lelouch by the first half of R1(or S1 but I like to call it R1 cuz it fits well with R2). Yea, she had help from her faint memory of seeing a highschool boy in a school uniform but it still is far from braindead which the critiques make the characters look to be.

Xing Ke also outsmarted Lelouch from pure strategic and tactics, without the use of any asspulls or deus ex machina. Yea, Lulu did underestimate him but Xing Ke won fair and square. And the narrative has made him appear as an extremely competent individual and far from a stupid side character.

Schneizel also had lelouch outsmart many many times right from the get go. Lelouch isn't the fondest of Schneizel and he is constantly a pain in the ass for him. Plus, he manipulated BK into betraying Zero(although that's a whole lot of mistakes made by Lelouch that led to this point). His plan to have Odyssus marry Tian zi was cunning and he is far from stupid.

Now, this is not to say CG only contains genius characters. The school episodes are quite silly and the cat chase sequence was definitely stupid(but that was the point of the entire silliness besides suzaku getting accepted by ashford academy) and the million zero is jojo level of unrealism.

Ohgi is quite dumb at times or overly emotional with his reactions. Euphy isn't the brightest. The betrayal was also quite dumb from BK part(although the deal of Zero for Japan was a steal) but the thing is---These "dumb" moments actively go against Lelouch and doesn't favor him, infact, they pose as an obstacle rather than help him.

Another silly criticism I find Code Geass is well...Teenagers. It's funny many "adults" criticize it when the literal demographic is young adults. And If I really wanna be nitpicky of this criticism then,

Lelouch is the highschool but he is an exiled prince and extremely intelligent and many themes go around him being young and stuff.

Suzaku is teenager but he really comes into relevance to the political picture after jeremiah frames him for the murder of clovis and the knight of euphy which eventually leads him capturing Zero in R1. Oh and he's great kmf pilot too.

Kallen is mostly there cuz her older brother, her sense of justice and her being ace pilot.

Nina is scientific prodigy but isn't involved with the political world of CG. Same can be said for Gino and Anya(specially with Anya given she is also the vessel of Marianne).

Kaguya, Nunnally are there cuz of the status they were born with than their competence.

It's also funny how many "adults" criticize CG for this aspect but nobody bats an eye on Monster where Johan literally did money laundering at age 15 and was a notorious criminal while being a teenager in underworld(literally running governments) or Legend of the Galactic Heroes where Reinhard/Kircheis are also young adults(teenagers literally and being better than admirals who already had experience of so many battle) or Julian mintz, the disciple(?) of Yang, being a better diplomat than bureaucrats or politicians of alliance(altho, there is an important theme of the show) but it's still unrealistic for a 15 yr old kid to be better diplomat than even a corrupted bureaucrat.