Rivens fail to bring the actual weak weapons on par with some of the strong ones

[ArmsForPeace84]

My Cassowar riven has helped secure its place as my go-to melee status stick, even though I have builds for Lesion and Kronen that are objectively better on stats. I just like the feel and moveset of Cassowar better. And it's still killing things quickly in Steel Path, so I stuck with it. So that's at least one riven that has taken something I enjoy using, but which is decidedly not top-tier, and kept it viable.

The biggest problem with the riven system, when it comes to even lower-tier weapons, is that you have to commit to a catalyst and probably 3-4 forma, to get a build that can accommodate the riven AND the mods needed to, potentially, make something of a weapon otherwise destined to remain MR fodder.

Opening up the simulacrum to allow free placement of virtual catalysts and formas would help a lot, here. Then if you're digging that build preview, you go work towards putting it together for use in actual missions.