7 Reasons Marvel's Movies And TV Shows Will NEVER Connect More
2. Not All Heroes Are Needed At The Same Place, At The Same Time
Have the Avengers really missed Daredevil's relatively limited skills in any of their cinematic adventures thus far? There's nothing wrong with street-level heroes staying right where they are and taking care of problems that don't even register on the Avengers' radar.
Stakes are often relative: what goes on in your neighborhood may not matter as much to the rest of the world, but it matters a great deal to you. From your perspective, the stakes are high when you or people you know are going to be impacted and anyone who helps swing the odds in your favor is making a huge difference.
In a world populated by more and more superheroes every day, each new hero will inevitably be less newsworthy on a global or even national scale. Each story becomes more compartmentalized. When part of Sokovia is lifted into the sky and blown up, Jessica Jones and Daredevil are not going to make national news by cleaning up Hell's Kitchen.
When the Avengers (and likely the Guardians of the Galaxy) battle Thanos in Infinity War, there may not be a big enough role for a character like Daredevil in those movies. Luke Cage, Jessica Jones, and Iron Fist seem like better candidates based on their power levels, but they may not be called upon either.
That will not mean that what they're doing during that time is unimportant of course; we can still learn about the Defenders' role during those events in their own series.
These stories are not about certain heroes eventually being "promoted" to Avengers status. They can be, obviously, but it's not like the TV heroes have anything more to prove to be considered heroes. They may not be saving the entire world, but they are saving what essentially is the world to a great many people.