i know this is not the first time someone's made a thread like this or constructive criticism like this, however, the problem is Warframe is still a FTP platform. They have to do things and MAKE SACRIFICES so people buy and spend platinum (in game currency). Yes it would be nice to have a system so we can get better rewards, but then no one would play their game because it would just be too easy to get things.
i could argue that i know of certain assasinations and mission types that can be its own "sortie" like a super or ultra sortie you can do once a week. and yes this is where you can