So a lot of discussions about the game come down to balance. Is it a goal? Should it not be a goal? I really hope this doesn't bog down in arguments, as all I want is opinions. I have my own feelings on the topic, which often clash with those of others. Every gamer is different and has differing desires for a game system.
I marked this as a 5e discussion since there are rumblings of changes in the game's future, but obviously, this topic is applicable to any game or gaming experience. I'll start with my personal view.
Let's compare game design to music. In the studio, bands can spend long hours, weeks, months even, searching for that elusive quality- perfection. You have a group of creative people, working together, but trying to push their vision to the forefront. The result is a mishmash of different takes, take a little bit from session A, add in a bit from session B, maybe use that awesome drum solo from session C, and sure, we can keep the xylophone bit to please our producer, but then overdub it to the point it's barely audible on the final track! If you did your job right, you have a classic on your hands.
Otherwise, it's a hot mess.
But live? On stage? It's not about perfection. It's about the moment. Connecting with your audience, and blowing them away with your passion and energy. So you're exhausted from touring. You're all out of tune. So you forgot some of the words (decades later, people will remember the time you quipped "does anybody remember laughter?" in the middle of a song). Your drummer decides this would be the perfect time for a 20 minute solo! It doesn't matter, as long as everyone leaves the auditorium energized.
Thus I feel balance is a goal at the design stage, where everything is white room simulations. Get the game running like a fine tuned machine. But be fully aware that, for the players, it's about the moment when Bob's Rogue jumps on the back of a dragon and stabs it in it's eyes! When a Wild Surge explodes in the face of your Sorceress, but takes out the BBEG (or just turns her into a tween girl). When the Barbarian rolls a 1 when trying to dive off a cliff into icy water, lands in the rocks and vanishes into the brine...only to throw a thumbs up out of the water and say "it's ok, I'm fine!" after taking 50 points of damage.
In these moments, the rules need to be able to fall away, and not interfere with the story.
But balance is important. If one class does a thing better than the other, and doesn't seem to give anything up for that privilege. When one Feat is simply better than another in every way. When two spells of the same level have wildly different strengths. That leads to questions. Is this feature too strong? Broken?
Or is the other too weak? If one player is getting too much "spotlight time", or another has an ability that trivializes challenges (be they combat or otherwise), then we switch from "balance isn't important" to "what the heck is this over/underpowered garbage doing in my game?".
Games have rules to resolve conflicts. Otherwise, it's all cops and robbers. "Bang bang, you're dead!" "No, I have armor!" "I shot you in the head!" "You missed!"
I feel we need to be able to trust these rules to function when they are needed. Not "well we didn't fully balance the game, but you can figure that out". By that same token, you could create a game where the rules work perfectly fine, and we can figure out when we can ignore them, no?
Obviously, comparing apples and oranges is impossible. We know that Fighters are supposed to be strong in combat. We know that Rogues have many more out of combat options than Fighters. So obviously, no one expects Rogues to be able to fight like Fighters. But at the same time, we don't want to get into a fight and have a Rogue stand around and plink things with arrows and try not to die! Perhaps like me, you saw way too much of that in the murky past, when Rogues were called something that started with a "T".
But the reverse is true. We don't want Fighters scratching their heads and looking dumb when the game shifts to "so we need to infiltrate the Slaver's fortress". We need a game that says "no Rogue? no problem!"
And yet...when we give ways for other classes to succeed at these tasks, we run the risk of trivializing the Rogue. Stealth mission? "Hey I can cast Pass Without Trace! or Invisibility!". Sure, those are limited resources, but it doesn't matter if, that one time the Rogue was like "alright! time for me to shine!" and another character, who already has had times to shine, comes in and steals their thunder.
A lot of this falls upon the DM/GM/ST/Judge/Referee to balance. To create scenarios where that shouldn't happen. Or hand out nerfs to abilities that are working too well/buff abilities that aren't working well enough.
The question I always have when this occurs is "did it have to be this way? Did the developer of the game think to themselves 'say, this is a really good option? too conservative?'. Or were they just tasked with creating 30 new spells to round out a new product for sale?".
And that's why I think balance is an important goal. Otherwise, you could just as easily create your own game (such as the version of D&D under construction on these very forums).