All our lot wear collars 24/7 pretty much, unless they are being groomed etc. In the UK, it is a legal requirement that dogs wear a collar with an identity tag, though I am unsure whether this extends to being in the home, or just when out and about.
I think collars have their dangers, but only as much as anything else i.e. A dog could catch the collar and choke, but they could also choke on some rawhide, swallow a toy, get hit by a car... It's up to us as responsible Mum's and Dad's to make sure they aren't put in a situation where these innocuous items could become a danger.