Sacrosanct
Legend
While true, the Battle Master gets Feats and all of its maneuvers and extra damage.
What wasn't what you argued though. What you said was this:
" It seems they entirely left out the 3E Fighter gameplay style. Where you had always available combat options by having a bunch of combat feats to tailor your Fighter. "
And 5e does have that. So you're incorrect, 5e did not leave out that gameplay style.
With Remarkable Athlete a Champion would only gain a +1 to +3 to an improvised action. I don't really consider that to be a big benefit, especially when the Thief Rogue basically gets to make an improvised action as a bonus action.
In bounded accuracy, any bonus is important. But the fact that it exists proves your claim to be objectively wrong. They can do more than just attack, and are better at any improvised action for a check that falls under STR, DEX, or CON