My core issue with the Playtest fighter is the same as the 2014 fighter.
The Fighters doesn't knew anything new in the base class.
The fighter as they level just gets better as using the the stuff they can do at level 1.
- The fighter attacks better as they level.
- The fighter saves better as they level.
- Most Mastery is better versions of normal actions. All of your DM is decent at adjudication.
The difference between a level 8 Knight of the Realm and a level 1 Aspiring Squire is numbers not capability.
All instances of gain capability is a feat or subclass feature, not a base fighter feature.