Excessive chewing needs to be brought under control, IMO. It's particularly not good if they are ingesting what they are chewing, which can lead to trouble and vet bills. Yes, it is hard to control chewing done when you are not present, e.g. chewing up their bedding, but I would actively discourage the chewing of things not designed to be chewed when you can. Remove the object and replace with something "legal". None of mine has been a real problem in this area, and my last boy, Perry, was taught by his breeder not to chew and never did. All his plush toys remain undamaged, although he was happy to carry them around or retrieve them to me by name.
A dog may chew because it has become habitual, but I would want to check his teeth if the chewing is excessive....