There really is nothing to do in Warframe.
Yup. It's a cashgrind MMO like every other. The only difference is we have guns, swords AND magic where most games of one or two at most.
Until Warframe adds something equivalent to dungeons and raids that actually requires all this snazzy equipment we grind for hours to get, it's just collection and epeen. Trials aren't like normal raids btw; they are just puzzles with enemies that are optional to kill, I mean big bosses that clear the squad if somebody doesn't do their job right.
Somebody said it better than me: "Warframe is all surface with no depth." I agree with that statement, and while I still play every day, clearing raids, putting a couple Forma on weapons I don't normally use just for a little change and getting my daily Focus Grind or doing Sorties to hope for something other than a sculpture, I never really feel like I accomplished anything more than the day before. There's nothing for me to truly test myself against.
DE, real endgame when?