He wasn't a mainstream fan favourite character until the MCU made him one via films and TV show.He's been in 6 big budget movies. Many of them as one of the main villains (including the first Avengers movie).
Ironheart is just a new generation character, that hasn't sold comics. Like usual, instead of trying to be her own character, with her own abilities she's mooching off of Ironman.
If you keep putting out the same charts year after year people will stop watching.