Yeah its not like we got Hank Pym to star his own films and joined the Avengers and Scott Lang replaced him to lead the Ant-Man films. The general public probably doesn't know that Hank Pym was the more essential character/ has the longer comics history as Ant-Man than Scott Lang. Though even with their decision, I wish they had Hank / Janet in the action as Ant-Man and the Wasp over the legacy characters from the comics. If I was an Ant-Man or Wasp or Avengers fan, I would have been pissèd off.
The Ant-Man case wouldn't be the same if Iron Heart, Ms. Marvel, Miles Morales got their own films in the mcu as we already got Tony and Peter headlined their films with their respective superhero name. Even if Carol wasn't called Ms. Marvel in the mcu, she's still THE Ms. Marvel to me.
Speaking of Carol Danvers, to me before her film was released, she was already more familiar to me than Mar-Vell so I didn't mind they tossed Mar-vell over Carol. However, they should have kept the Ms. Marvel identity as (before the movie came out) it was more iconic, personally speaking.
And people say, that some of the legacy characters are more interesting than their precedessors... then why in the world they were turned them into a legacy character by taking the mantle of an already popular or well developed superhero? Iron Heart will always be seen as Iron Man 2.0 no matter how great she is. Miles will always be called the 2nd Spider-Man or replacement or another version of Spider-Man.
And yes Lazyness was part of their creation, because for Marvel Comics it would be easier to build up Miles / Gwen as the new Spider-people... instead of selling them to the public as Grasshopper Man / Butterfly-Gwen. Its the reason why we have so many Spider-people, Wolverines, characters with the American flag, inspired costume similar to Steve, characters that can into the Hulk... its coattailing the popularity of a certain character. next thing we'd get is a legacy character of Dr. Strange and Shang-Chi in the comics.