I'm A Banana
Potassium-Rich
I don't think that trading off between the pillars is a great kind of balance. At the extremes, it leads to players twiddling their thumbs in scenes where they feel like they can't make a contribution because it's, say, an Interaction scene and "I've got an 8 Cha, I can't do anything!" Ideally, you want broadly capable PC's who can contribute to every pillar successfully, and then they can maybe choose a specialization if they want to double-down on a pillar - and maybe someone can choose to "ignore" the pillar if they want to, but they'll still be fine when it needs to happen.Seems like a fine goal to me. In a role playing game with 3 main pillars of activity, making the fighter class the best at fighting doesn't run in the face of class balance at all. Fighters are supposed to dominate fights, other classes are supposed to dominate interaction and exploration.
The idea that all classes have to be balanced around fighting alone is short sighted unless one is designing a game of pure combat.
5e seems to follow that model in most respects. A Champion whose player really wants to tank their social skills puts an 8 in Cha and doesn't take any social skill proficiencies (even from their background!), so maybe they're an Urchin with proficiency in Sleight of Hand, Stealth, and Acrobatics and Perception. Lo, they are actually quite good at the Exploration pillar without really trying (even a low Dex or Wis here would be a 10 with the Standard Array, which is fiiiiiine with Bounded Accuracy). And even this clod can make a Charisma check, and stands a chance at succeeding despite himself (a -1 can still roll a 17 and DC's are bounded). So if everyone else is dead and it's on him to persuade the mind flayer not to eat him, he can still stand a chance. There's never nothing he can do.
So you have a broadly capable character who, even in the area they "dump," isn't a waste of space. This points to D&D 5e not really trading off pillars like that - you don't get good at Combat by sacrificing something else. Everyone is about equal in Combat, and if you choose to "dump" it (say, a wizard who refuses to take anything other than ritual spells), you'll still do fine (cantrips!), even if you won't be pulling out any surprises.