Maybe “redeem” is not the right word here. I don’t think Feige and company didn’t anything that requires actual redemption. Not everything was prefect before Phase 4.
However, less is more. I understand a lot of heroes and teams in comics had their own self-titled comics, but when it comes to film and TV, I don’t think every hero or villain needs their own film, trilogy, or even series. Back when Marvel Studios was just doing film, I was okay with Avengers like Black Widow, Hawkeye, Vision, and Wanda not having their own films. We still learn about them from the films they were in.
I think the idea of introducing new characters via series is a great idea, but not if it does cause them to run thin on resources and creativity. If more time is needed, then give yourself more time. They make their own deadlines, so in some way they are competing against theirselves.