This is something we discussed in length before Forsaken with the team.
An issue that arose was potential exploits around various perk setups that could be pointed at as pay to win. Additionally, it would break some of the limitations of other sets - Why can players only reroll armor via Bright Dust, but not other items via shards and other currencies?
At this time, we do have the ability to reroll Sparrows and Ghosts, but that's in part to their limited perk pool. It gets a bit more technical for other gear, and it's a pretty large chunk of content that would take time to develop and test which could impact other QOL development.
The team is aware of the feedback points surrounding armor and collections. We'll bring this forward to the team to make sure Eververse sets are also a piece of the conversation.