So you agree the only way Cap can beat Iron Man is with help.
No help, close quarters or open area, Iron Man beats Cap every time.
This really means a lot to you, doesn't it ?
I will agree that in Civil War Cap was able to overcome Tony with help - granted for most of that fight Bucky was running away - and I will totally agree that after Tony blasts off Bucky's arm, and then uses Friday's computer tactical skills to find a way to overcome Cap in hand to hand (using a combination of both fists and repulsor blasts) well at that point Cap was pretty much beat.
That "stay down, final warning" bit, at that point if Bucky hadn't distracted Tony, that would have been the end of the fight......... but then that momentary distraction allows Cap to seize the advantage and defeat Tony comprehensively.
In close quarters using fists and shield and Tony only using his fists I think Cap could possibly take Tony = mostly because using just fists and the shield he was able to smash through Tony's armour, rip off his helmet and disable the arc reactor.
However, once Tony uses repulsor's and Friday's tactical program, well Cap's screwed.
However, at long range or in open ground Cap is at a massive disadvantage, and if Tony used those factors to his advantage he's going to beat Cap pretty quickly.
Cap was able to hold his own against War Machine, for a short time, in CW because Rhodey engages him at close quarters.
This is the movie versions, the comic book versions are a very different story: Tony beats Cap pretty easily.
Feel better now ?
( and Gamora would only last a few seconds against Iron Man)