It would be nice to bump up the frequency of system/frame reworks a bit, though right now it seems they're 99% focused on New War. On the other hand, a lot of old frames have received indirect buffs or otherwise gained new life through new mods or features such as shield-gating and the Helminth. I can use Banshee in Steel Path, wtf.
I got the second Harrow systems blueprint (for feeding purposes) on my second attempt. :smug:
defection still sucks
To be clear, I'm fine with most Warframes as they stand now (except stuff like, say, Nekros). The game for the most part needs not so much reworking of old content as it needs pruning and streamlining.
For example: Nightmare Missions, Arbitrations, Sorties, the Steel Path and many other modes serve (or rather, attempt to serve) the same basic need; endgame content for progressively overpowered players. But having so many variants of the same basic template (take this existing mission and make it harder), each with their own, slightly different set of rules and its own rewards, makes it so overcomplicated for many players to keep track of, and by and large does not offer a significantly different experience from even playing the stages for the first time, just higher numbers to keep up with the insane power creep from mods. These modes are, for the most part, haphazardly half-assed in terms of design, and having so many means that the playerbase gets fragmented. Many of them, like Nightmare Missions, serve no purpose at all after collecting all the rewards, so the game commits one of its most frequent sins which is to try to make something relevant again by throwing in Nightwave missions to force the players to play them. Nightwave is good as a concept, but whenever it's used to push players towards content they don't normally play, it should be to incentivize them to play content they may not have experienced yet, not content they have exhausted.
The vast majority of the above modes should be removed from the game in favor of a single, cohesive endgame mode that gets all of the attention and design resources. Keep what works (e.g. Nightmare mission modifiers are neat and can change the way you play missions; arbitration Warframe buffs are also a neat idea that just needs a better mode to be attached to; Steel Path's increased enemy endurance is a first step if halfway solution to the game as a whole becoming trivial) and make a single, cohesive mode out of it all.