Reddit reviews The Voice and Voice Therapy

My voice textbook actually recommends glottal fry as a possible treatment for nodules. The idea is that, when you're in pulse register, your VFs are only loosely adducted, and held there with relatively low tension. As a result, they're more "malleable" than when producing higher pitched sounds. They gave this metaphor: If you place a pencil (the nodule) between the pages of a textbook (taut VFs), then it prevents the pages from closing completely. Conversely, if you place the pencil between two marshmallows (lax VFs), then they fold around it. As a result, you're able to phonate without continuing to putting excessive pressure on the nodules, which actually gives them a bit of respite and can allow them time to heal.

However, this is not to say that glottal fry is good for your VFs in general. It's only shown beneficial in the short term for this specific vocal pathology. I also haven't seen any research into how phonotraumatic it is to use glottal fry in the long term. Considering that it's a normal feature of prosody or phonology in a lot of languages, like you say, I'd imagine it wouldn't be damaging unless you're using it a lot, but that's just a guess.