I understood what you said, and I'm sure he did as well. Honestly, I think it's you who is not getting what I'm trying to say. The game is not "combat only", and you can't compare "combat feats against other combat feats" for this reason, as well as the reason that they all overlap under the greater umbrella. Combat, interaction, and exploration aren't all separate things that don't impact one another--they more often than not all overlap and impact each other. Exploration or interaction may allow you to overcome a combat challenge rather than combat. And vice versa. They are all intertwined. At least, that's how the game is designed to be played. See my examples I gave earlier about how some classes seem way OP to others depending on if you allow short rests all the time or not, or if you ignore other factors. Gaining and maintaining spell components is very much an out of combat action, but it very much impacts the combat encounter unless you (general you) choose to ignore it. So you can't really complain casters are OP when you're ignoring features built into the overall game that are meant to mitigate these things.
For example, even if you look at two "combat" feats: heavy armor mastery and grappling. A person who views D&D only at a tactical combat sim will probably say grappling is worthless, especially compared to heavy armor mastery that is basically a damage reduction mechanic, so it's not balanced. But D&D is not meant to be played as a tactical combat sim, and those out of combat factors play a huge role. Maybe they party is in a desert, ocean, or jungle, and wearing heavy armor imparts serious penalties or can't be used at all. Or someone casts heat metal on the armor wearing guy. In those cases, being able to grappler would have a much bigger impact than heavy armor feat.
The point is, is that you cannot separate the three pillars into different games. That's bad methodology for whatever analysis you want to do, because that's not how the game is designed to be played. If all you're doing is evaluating white room arena comparison, then some comparisons will seem very unbalanced because they are designed knowing that other factors from the other two pillars will have an impact in the typical game (like how the availability of spell components is not a combat pillar feature, but very much has an impact during the combat phase). So if you choose to ignore the other two pillars, the onus is on you to make those adjustments because you're the one skewing some abilities/feats to be artificially more impactful than others.
*Edit* Also, not myself, or anyone else, has said balance doesn't matter and/or nothing else matters. I'd appreciate it if you'd stop slinging around inferred insults of nihilism based on a strawman. The original context of my replies was around how someone said they can "break the game" by a build, and I disagreed. When myself and others have talked about balance, of course we all agree that there has to be a good foundation, but only that it's completely subjective, and all factors of how the game is designed to be played should be taken into account, and therefore if you're playing the game as an exception to this assumed design, then it's up to you to make adjustments, and not the game's fault of refusing to balance like you want.
One of the early complaints was that PC numbers didn't keep up with monsters, not vice-versa. It was addressed (and over done, IMHO), especially in Essentials, which introduced & re-introduced many balance issues, while simultaneously becoming more parsimonious with errata. In retrospect, a faltering first step towards 5e...
