I think the next logical step would be Thunderbolts or Dark Reign. Something in which the gov't gets involved and creates their own sanctioned Avengers team. This single villain stuff is becoming pretty redundant, with them fighting faceless goons. Of course Thanos ggave them that work and the BO was good, but we need more of that.
actually you"re right. Dark Reign IS the next logical step!
The government has already tried to get them to heel and it didn't go over well...
next step would be to create their own team/superheroes.
Hell, you could even get the ball rolling with Osborn in the next spider-man movie.
there's a distinct lack of high powered villains in MCU. Strange, now that I think about it