The feat is good enough that it's well worth taking at level 4, putting them ahead of Sword & Board despite the lower Str. And no the fighter isn't "at or below the cleric" at levels 1-3; Second Wind and Action Surge are both pretty impressive abilities compared to level 1 spells and at least some subclasses, like battlemasters, are solid at level 3 - and the dueling style lets you hit harder than the cleric will with a longsword. Basically you give up 1 damage per attack Vs a longsword at L1-3 which isn't the end of the world.
As for the non-combat stuff, I disagree. Again taking a battlemaster as your build you get your background at level 1 - and at level 3 you get three maneuvers and you can afford to give up one of them without serious costs (because you still have your best two picks for combat) to get the ability to use superiority dice on History, Investigation, or Insight.
When the only actual problem is one damage per hit compared to a longsword I'm not seeing the problem as huge.
It absolutely does scale to Tier 2. Various feats are close to gamebreaking in T1 and ASIs and the good combat feats multiply the effect of each other so you generally get a lot of benefit from two ASIs and one feat (two in cases like Sharpshooter + Crossbow Expert). But this caps out after three.
The fighter however almost stops scaling at L11 (or in rare cases L12); they have a complete Feat + Full Stat combo, and three attacks. This is definitely a T2 combo and should utterly roll anyone in T1.
The Barbarian is a worse case, stopping at L5 or 6 with a good subclass. Their levels 7 and 9 features are meh and bad respectively, and their level 11 feature looks good on paper but in practice it will stop half an attack then you'll go down to two papercuts. And you don't get the closeness of the multiplier in the 4-6-8 ASIs
Again the issue is that unless you are a human, you don't get feats until the earliest level 4. That is the last level of Tier 1.
So making a class that only does what it say from level 4-11 is iffy if the book goes from 1-20. And some concepts and archetypes require 2-3 feats to work.
That's the issue I keep bringing up. If you want the fighter to encompass 30 different warrior archetypes, you need to give it the mechanical space or claim mechanics don't matter. But you can't stick 30 archetypes in 6 pages.