This is an example of what frustrates me and other gamists. The "DM is subjective and everyone plays different" argument is a nihilist excuse for poor balance. Just because some guys play all combat encounters, or some play all roleplaying encounters, or some DMs throw all ranged attacks at people, doesn't mean you can't or shouldn't balance the game. Balance is done for the norm/mean/average and is on a sliding scale of subjectiveness as you narrow/expand your focus. For instance, when you narrow the scope down to balancing combat stuff against combat stuff, the subjectiveness narrows as well. If you have 2 feats, one of which gives +3 with swords, and the other +1 with swords (and they don't stack) it is entirely factual - and not the least bit subjective - to say the two feats are imbalanced against each other.
There are many, many of us that play D and D as a tactical challenge. Combat abilities can and must be balanced between each other to have a good game. Of course a silly DM can throw a monkey wrench into things by having all ranged combats or other ridiculous scenarios,and of course there are some people don't have combat encounters - but that doesn't then render balance pointless or subjective from a design view - it just renders it pointless to those people. And if you are one of those people, why would you argue against modifications? It doesn't impact you anyways!!!
Firstly, I don't appreciate being called a nihilist. Secondly, it's not true at all, and you're missing a very important context. That is, D&D is not designed to be a tactical only game. If that's what you prefer and you like to play, more power to you, but you do not have much a leg to stand on when you complain about how something isn't working or say the game is "bad" when you're ignoring the core premise of what the game is built on.
And what is that? The fact that it's an open world RPG, not just a tactical boardgame. Why is that important? Because it assumes the core game will be played in a living world, where every creature has motivations, and the terrain and regions all connect like a living world would be, and not played with one grid based battle after the other. Those factors
have to be taken into account then, and they very much affect the "balance" of the game.
For example, if you play just tactical encounters, then one feat with +3 is going to appear much more powerful than a +1 feat. But when you factor in how the game is designed to be played in an open world where that +3 feat has additional restrictions on when it may apply over the +1 feat, then the balance issues become a non issue and they in fact are balanced.
Let's look at the sharpshooter feat. It's always mentioned as a broken imbalanced feat way more powerful than any other feat. In an arena style or tactical style of play, I can see why that may be. But that's not how the game is designed. All of the other pillars are just as important and emphasized in the design window. So there will be times where the PC won't be able to use that feat very often (out of ammo, not in combat, etc), but someone with the dungeon delver feat will be using that constantly during a dungeon exploration. Is a feat OP when it's can't be used that often?
So while I get that "many, many" of you like D&D as a tactical challenge, that's only 1/3rd of what the game is designed to be, and you ignoring or placing low emphasis on the other 2/3 is not a game design issue. That's a
you issue for choosing to play in a way the game is not designed for. Especially when factors in that other 2/3 of the game do impact the mechanical balance. It's like complaining casters are way too overpowered and the game balance is off when you let them rest whenever they want, ignore spell components, etc. Or saying warlocks and monks are overpowered when you allow short rests after every encounter. I.e., your choices are skewing some things to be more impactual than they would be in a style of play that the game is designed for.