I thought about making this a separate thread, and maybe I will at some point, but instead will make the following two points quickly-
1. Revealed preferences. As I have noted repeatedly, Fighters are the most popular class. That means that despite what people keep saying, they are always the single most chosen class. So when people sit down and decide what they want to play, out of all the classes, they choose fighters. Now, you might say to yourself, "Well, if we had better fighters, then maybe they'd be ever more popular!" Okay. But that would be a problem. As it is, Fighters are too over-represented. Imagine if they went up to, say, 20% of all the classes picked. That would be more of a design issue that what they have now.
2. Fallacy, revisited. The issue with the crab bucket "fallacy" is, as noted previously, with the premises. In other words, at any given point, it demands balance (without defining what that is), assumes that everyone agrees with the unstated assumptions (that martials are all "underpowered" and that spellcasters are all "overpowered"), and finalizes that by assuming the comparative set (we must compare martials to spellcaster, because that's the accurate comparison, not martials to martials).
In all three aspects, there isn't agreement.
A. People don't agree on what balance is, and how it's defined, at any given point.
B. People don't agree that martials underpowered, and spellcasters are overpowered.
C. People don't agree that unlike things must be compared. In other words, saying that martials must be compared to spellcasters is not the same as saying that a given first level wizard spell must be compared to a given first level wizard spell; instead, it's saying that a given third level wizard spell, cast by a specialist wizard, must be compared to a similar third level cleric spell, in terms of damage. So a person says, "Well, the cleric doesn't get fireball, so ..."
Just imagine running the comparison backwards. "My wizard doesn't get your hit points, or armor choices, or weapon choices. I can't do any of the athletic feats you do. If I wanted to, I'd have to blow all sorts of backgrounds and feats and do all these other things to make my character less cool. Why don't I have exactly what you have?"
TLDR; more often that not, it seems like the majority of these threads are just a backdoor way of arguing about the warlord. Which, okay? I hope people get a class they like, or use homebrew, or use a 3PP. But just because you want something, doesn't mean that other people have (to quote the OP in a later post) "invalid opinions." We all have valid opinions, just some of those valid opinions happen to be enabled in 5e right now, and some aren't. Most of my valid opinions aren't in 5e, which sucks, but I deal with it.