That, or... recognize that combat is only one pillar, and that there are many ways to optimize, and thus contribute, in many facets of the game
You can do it with any character. In fact, 5e makes that easier than any previous edition to be the case.
Simultaneously on all the pillars?
You can't do that with any character
The problem here is that the Wizard has plenty of limiting factors that aren't often taken into account by Gap Truthers. Sure, flexibility is the Wizard's greatest strength... it just happens to be in a game that, by and large, rewards specialization over generalities. A wizard can always serve as a bit of a swiss army knife, but there a multitude of situations a swiss army knife just isn't going to cut it at, and plenty of others where a more specialized tool in the shed will prove far more useful
In less important situations, you have cantrips to grind damage all day, skills (just like everyone else, likely more than some), non-combat cantrips, and, if time isn't the issue, rituals.
Combine that with combat being the vast majority of the game and the other “pillars” only having vestigial support…
That, or... recognize that combat is only one pillar, and that there are many ways to optimize, and thus contribute, in many facets of the game
I have never seen this play out like this, ever, for a number of reasons that only really exist when you're actually playing the game with living, reasonable humans.
Players can overshadow other players with absolutely no input from the game mechanics. And the solutions for the GM mitigating it are exactly the same.
Stepping away from D&D and TTRPGs for a second, there are cooperative board games like Pandemic or Forbidden Desert where players pick “characters” that have different actions or moves that they can do on their turn. What people quickly learn is that some roles are above and beyond better than other roles. So some roles will be consistently picked over others because the things they do make victory or accomplishing certain tasks easier. I remember my partner’s sister playing such a game with us. She picked her character but she felt overshadowed by the other options and more to the point, she felt as if she wasn’t able to contribute as much (if at all) to winning the game. So when we finished the game, she felt incredibly dissatisfied and underwhelmed by the game, even though the players who chose the “essentials” felt much better about the game because they weren’t overshadowed. I think about that a lot because I seem to recall that some of the later games after Pandemic balanced roles much better, leading to greater player satisfaction across the board when picking different roles that they want to play.
Yeah I guess I should have specified TTRPGs
Yeah, I guess I should have specified what I thought was obvious that my point about imbalance in cooperative games extends equally to TTRPGs because I have seen similar experiences all too many times.
I can't comment on the hobby as a whole. But I play, or have played, plenty of RPGs in which some important characters' principal strengths are not combat - Classic Traveller, Prince Valiant, Burning Wheel, Torchbearer, to some extent Rolemaster, even to some extent the invoker/wizard ritualist in my 4e D&D game.
I think some of the fun with Pandemic (for me) is the randomisation of characters selected by the players as we do not pick. We played the hardest level and weirdly never once did the Medic come up. We won only on the 5th time and only by the skin of our teeth.
I don't know how many more different ways there to explain that in a TTRPG that there are so many ways beyond core game mechanics to make an impact and contribution to shared goals that the need for balance becomes vestigial.
