Daredevil could be the tent-pole property for an entire new tier of Marvel movies. Tie together Daredevil with Power Man and Iron Fist and Punisher using Ben Urich as the link character ala Coulson, with Wilson Fisk as a recurring villain.
I like the idea of adding more non-Avengers films to the MCU, just to broaden it still further, but I'm not sure those other films would really need to build up to a single crossover like Avengers
. No reason the whole MCU has to be locked into a single formula. It might be better just to have these films in a common universe and have occasional overlapping elements or characters, or maybe smaller crossovers or guest appearances.
On the other hand, your suggestion here is kind of cool, especially the Ben Urich part. Except I'd be happier if Daredevil and Spider-Man could be under the same roof, movie-rights-wise. After all, Kingpin was originally a Spider-Man character (and so was the Punisher, for that matter), and Urich has often been a semi-regular figure in Spidey comics as well as DD; plus Spidey and DD have often swung in the same circles themselves.