One way to tone down hard-cc would be to make them give decent bonuses. I'm not sure if this is the case already (as was in D:OS1), but being frozen could give you a boost in armor and resistance to slashing, for example. Knocked Down characters should be harder to hit with ranged attacks. That sort of thing. I don't know if that would make much of a difference, but it'd be start, and you'd have to think about how your CC synergizes with your whole party more.
That's thinking in the right direction here, IMO.
Totally agree on these points.
