Actually, the wizard is awesome at the social pillar. The error is thinking the social pillar is spamming Cha(Pers) and Cha(Decep) checks.
Lots of Int(His), Int(Rel) and Int(Arcana) to understand what people are talking about and ask the right questions. Lots of Int(investigation and Wis(Insight) checks to read people. Wizards are great of these, since a lot of them are Int based and many wizards also have good Wis.
Of course, let’s not ignore the other part of the social pillar: actually being able to communicate. The 18 Cha Rogue isn’t going to face very effectively if he doesn’t speak Giant. Tongues and Comprehend languages definitely give wizards a boost here.
Can other spells give wizards a boost in the social pillar? Prestidigitation is a good way to impress commoners. Detect thoughts is pretty good also, and doesn’t require a saving throw for surface thoughts.
I think this is key to some of the disconnect. Wizards are ok to great at exactly replicating the way other classes can contribute to goals (melee damage per the 8 attacks per round point, high cha (per) checks, etc.) but they ALSO can contribute meaningfully to those goals in other ways and are often better off doing so.
Winning combat is the goal. Doing the most damage is a potential means of contributing.
Getting the King to declare war on X is the goal. Beating Cha(per) is a potential means.
A Wizard could research that the King is still blaming himself for not acting on his wife's advice leading to her death. The Wizard creates an illusion of his dead wife telling him to declare war.
The more and more flexible resources you get, the more and more ways you can contibute to goals.