Dessert Nomad
Adventurer
Fighting styles are significantly more powerful than feats, in my opinion. There's no feat which is as powerful as +1 to AC, or +2 to every attack roll you ever make. They aren't flashy, but they apply so frequently that they're on par with raising your primary stat, which is more than can be said for the vast majority of feats.
As James pointed out, Dual Wielder gives +1 AC in addition to other benefits so it's inarguably more powerful than just a +1 AC. Toughness gives the same HP benefit as +2 to con, which I think is at least on par with +1 AC. The -5 to hit, +10 to damage feats (even without their other benefits) outclass +2 to hit or reroll 1s and 2s on damage IMO. The 'extra attack that gets stat bonus' from Crossbow and Polearm mastery is at least equal to 'you get stat bonus on the bonus action extra attack', and both of those have an additional benefit. War Caster is essentially required for an EK that uses a shield or two weapons. Yeah, the vast majority of feats aren't directly useful to fighters and many aren't even combat oriented, but the good combat feats overwhelm fighting styles with their benefit. You do have to be doing whatever the feat supports to get the benefit, but the same applies to fighting styles.
Also the +2 to every attack roll you'll ever make is only really true if you take Crossbow Mastery to remove the melee range penalty or Sharpshooter for the -5/+10, if someone's in melee range you're going to do better on average by whipping out a rapier than by firing arrows. You could still choose to fire an arrow, but it's not your best option if you only have the fighting style.