In the beginning the CC was something and damage frames was weak because their potential stopped scaling. Now the roles changed and now CC is what weaker. Basically both should be an equal option but the balancing is a never ending task for any developer so they probably need to do a mass revisit. Nerfing damage could not help because still the CC abilities won't be super useful if there are enemies what are immune to certain CC abilities. The problem is mostly the game core idea itself because the devs want us to be godlike mass murderers but in other hand they want provide challenge. Challenge can only be achieved if they can provide a difficulity what the players needs. The most certainly thing what can provide this thing is the pvp. The pvp is not beloved here because the game peer to peer and our ability spamming options are wide and noone like when someone using your abilities against you. The other option what they can do is adding more sponge enemies which simply has too many hp so cannot be killed easily or using ability immunity or any kind of status resistance. The star chart is doable with the basic modding route so the 4 base ability boost, flow, vita-redi plus 1 other mod and 1 exilus and a choosen aura. The difficulity is only the one shot enemies on higher level but the star chart can be dangerous if you are not using the recent meta mods or augments.
The endless mission modes are in other hand has not strict scaling rules and the scaling in one point can goes rapidly. This game mode not meant to be balanced in your standards because this created to challenge your ability to survive as long as you can.
If they add a better AI the game would be more focused on single target challenges but the the horde shooter tag become useless. They hardly can do what the playerbase needs and everything what they tried mostly is pvp oriented becuse they know the pvp is the only real option when you wish to compare player vs player skills in a mode. Which is not that bad I certainly would like some capture the flag mode or siege like in the mount and blade series but the question is how they could balance our damage output?
Will they just remove the abilities or limit the damage of weapons can do? Or they just making a matchmaker revisit to scale the difficulity so probably you could meet with similar skilled players.
Anyway the CC frames still can shine because their abilities always will work on enemies on higher levels regardless it is 100 or 1000. The damage still fall fast on a point where the CC frames can shine well and be useful for the team. Most of these frames needs some self sufficiency which can be some damage, status remover, healing ability or energy replenishment so they can continue CC-ing. Frames like Loki is still useful and he is not changed too much because his design was smart and he can disarm the mobs with a press of button. He can go invisible and that gives him some extra dmaage which is not scaled but on starchart works. In higher levels also his abilities won't work 100% but that not meant to be in the first place. I am not arguing with the idea these and other damage dealer frames needs some tweaks but the starchart is the core of the game and that is the level for balance things. Endless missions just means extra things which can be done for better rewards which really needs fix there is the rewards itself. The scaling in other hand could be revisited but that itself won't help a lot becuse in the end they will instead nerf our ability to deal with the mobs than reworking a full system which mean the core of the game and not meant to be a darksoul.
In the developers point of view it is a hard task to stay attractive for new players and advanced players and please your veterans which probably will burn out sooner or later depending on what time they spent on the game. If the coop component become a crucial part of the game so we really depend on each other to achieve success in the missions then the gameplay will be slower and most players would leave immediately. Also if you get lower level or skilled players in your team you need to cater them and if the mobs harder to kill and have better tactical options then most of the skilled players will only play with their skill levels and left behind the newest players whom still don't understand how to play for example a survival.
A better tutorial needs, also some content levelling which is basically started with the addition of junctions and higher mastery reqs for weapons. This way they could make harder enemies which not instant kill you but give a much better option to beign challenged.
Sry for my long post, that is just my idea how I see it and I think the CC frames are not tragically bad at the moment.