I think everyone that tries CC does it because they're very sleep deprived, and their child doesn't know how to self settle. My opinion is that in these cases- when there are sleep association issues, like dummy dependence in your case- doing a version of CC that feels comfortable to you can be a life saver. As for it being 'damaging'- well I think if it's done properly it cannot really be damaging. By 'properly' I mean the parents doing it step by step, to a level that feels comfortable to them, & being able to follow through (because it's very easy to backtrack, in which case it'll become even harder next time).
My own experience was similar to yours. DS had a dummy dependence problem which only got worse & worse. He is now 9 months, but until 2-3 weeks ago he was basically waking every hour, crying for his dummy. We would replug it & he would fall asleep again. The situation had got so bad that both DP & I were dreading bedtime every night, & were close to depression (and desperation!) Finally we made the decision to ditch the dummy, & do it cold turkey:
--the first night DS cried on & off for an hour, with me mostly with him sh-sh-shing him & patting him.
--Second night 40 mins with me going in every 5 mins or so
--Third night 20 mins
--Fourth night he just rolled over & slept!
I also want to add that he stopped waking in the night (for his dummy but even for milk) from the 2nd-3rd night. Since then he's basically sleeping through, we sometimes hear him babbling away to himself but then he self settles.
This was such a big change in our lives that I can't quite believe it myself. I felt so down, so tired, so desperate; as for DS he was cranky & always seemed slightly tired, & now he actually seems much happier. Basically he's sleeping SO MUCH better & I really dare anyone to say how that cannot be better for him (and of course for us).
I won't pretend that CC is an easy option. It's not. It can be hard at moments. But for us it was much easier than we had thought, we never got much crying at all, and most of the crying was a 'self-settling' kind of crying, more 'on & off' than full blown screaming.
Anyway. When I hear people saying they're 'against CC' I usually think 'well they haven't been sleep deprived enough'. If they had been they would rethink their views IMO. And if not, I really am seriously curious what is the benefit of a whole family being so sleep deprived they can't think straight? Isn't that far more damaging, in the long run, to the whole family's health (mental & physical)?