Yes. Chroma is bad compared to many Warframes. No the niche he has isn't making up for it.
I don't know what people are smoking whenever i read that "Chroma is still a really good Warframe."
Where? His survivability is completely gone. Especially since the armor changes, even with max Strength build, all the Shards and many different survivability things stolen from other mechanics, a Steel Path enemy still sneezes at him and he dies.
Look. I have mained Chroma since he got released. I've maintained him day in and day out. Min maxed everything you can before the so called "fix" (it was a flatout nerf and you know it DE..)
I could facetank the Trial Raid the entire time without even being too worried about dying.
Once the "fix" rolled around, they sure fixed the damage calculation, which would have been fine, but backstabbed Chroma by also changing the calculation of his armor. After the nerf even with way more Powerstrength through other mods and sources, i still weren't able to survive even basic Steel Path enemies.
Now? With the recent changes?
The only thing you can still only kinda use him for is credit boosting. And even there he lacks being a reliable source with 60% chance now.
His survivability? Gone. Completely ruined. His damage? Outclassed by even basic Rhino Roar often. Teamplay? What? You gonna sacrifice even the little bit of survivability now so you can give your team a mediocre at best buff outclassed by so many other Warframes?
Even the heavily nerfed Dante is still leagues and leagues ahead of him EVERYWHERE.
You could literally revert every single nerf and "fix" for Chroma and he STILL would be dying when a basic Steel Path enemy coughs at him. So could you at least give him back his damage, if you aren't willing to spend the time to give him a proper rework?
Again. The very few niches he "has" are laughable at best.
Chroma. Once a Warframe worthy to be called the dragon is now.. a wet, soggy, snot soaked paper cutout of a dragon. And it saddens me to see it.
Suggestions on how to improve him? You would have to fundamentally change his kit to make him work in todays gameplay. Something i don't think we gonna have anytime soon. The best hope i can have for him is to have either at least give him back his damage, since survivability won't be recovered without something different changed. And that is something, even IF it is THE thing i would wish for the most, that just won't happen anytime soon.
Yes. tl;dr Even reverting all the changes won't make him a good Warframe that can survive todays gameplay. But at least giving back his former glory in terms of damage would give him SOMETHING again.