One thing you are overlooking is is the new Great Weapon Master feat also gives you +1 strength. That lets the new fighter not need to spend as many ability score increases upping his strength. A fighter can start with a 17 strength and by 8th level they can have Great Weapon Master, Polearm Master, and Charger as well as a 20 Strength.
Or they could start with a 16 strength, get GWM to go to 17 and then get inspiring leader and increasing their charisma, followed by Heavy Armor Mastery to get a bonus to con. Or they could have taken the ASI Feat and increased their strength by +2.
Yes, every single feat increases your ability scores. I like that design, but I'm not "overlooking it" because it is more complex than just "I can take all these feats to get 20 strength"
Just adding Charger adds an average 4.5 damage a round. That puts your new fighter's damage at 6.9 more than the old without advantage, and only 2.53 points behind if they have advantage.
Shocking. Great Weapon Master PLUS Charger does more damage than just Great Weapon Master. You do realize of course that that has nothing to do with looking at the two feats side by side? Because it is a third, unrelated feat. I might as well say that the old GWM does more damage because I spent 4d10 Battlemaster dice to add to the damage. It just muddies the waters.
I think people are seriously underestimating how powerful it is that all of the feats now give a stat boost. A new fighter can basically take twice as many feats as an old one. I was playing around and built a level 20 fighter and it is ridiculous how many feats a fighter can take, without sacrificing their ability scores.
I started with 17 STR, 12 DEX, 15 CON, 8 INT, 14 WIS, 8 Cha. At level 20 I had 21 STR, 14 DEX, 16 CON, 8 INT, 15 WIS, 8 Cha with Great Weapon Master, Polearm Master, Charger, Heavy Armor Master, Mage Slayer, Sentinel, and Resilient (Wisdom) and Epic Boon of Irresistible Offense.
The new fighter is Amazing!
So, what would happen to this AMAZING new fighter if they scrapped that change to the feats, and went back to the old way and none of them increased your Ability Scores? Would the fighter still be amazing, or is it the FEATS which are amazing?
This is what I keep trying to say here. People are attributing the change to the wrong place. This new fighter is barely better than the old one, all it has are the weapon masteries. The other things are things that were changed MONTHS ago, and are completely different parts of the rules.
Edit: I was just looking over the mastery properties in a little more detail, looking at different possible synergies between them. Correct me if I am wrong here, but a level 18 fighter can make up to 15 ATTACKS in one round, in every thing line up! All it requires is have Polearm Master and two weapon fighting feats.
Attack 1: Any one handed weapon. Attack 2: offhand attack with nick for free and sheath both weapons Attack 3: Draw Halberd and attack. Attack 4: Halberd free attack with cleave. Attack 5: Halberd. Attack 6: Halberd. Attacks 7-12: action surge to repeat 1-6. Attack 13: bonus action Halberd attack. Attack 14: Reaction opportunity attack. Attack 15: Haste Spell.
Yep, Fighters are AWESOME!
You can't use nick twice.
You can't use cleave twice.
Even with the Dual Weilder feat, one of your two weapons must be light, and you would have to start with both of them drawn, which also means you can't repeat 1-6 with the action surge.
Not sure why we are adding the haste spell, since Fighter's don't get that.
But, it does look like a fighter can do Attack 1, Nick free, Halberd 2, Cleave free, Halberd 3, Halberd 4, Action surge for four more attacks, Bonus action attack, and still have their reaction. Which is 12 attacks. 13 is we insist that the Fighter has haste on them.