They covered my city with them recently and I'm yet to see anyone use them for actual transportation. I tried Bird out over the Thanksgiving holiday with my parents for fun. The app was a bit complicated but overall were pretty fun. Riding the scooter felt a bit dangerous and I wouldn't be able to bring anything back from a store on a scooter, so I'm not sure when I would use one. Also you can't ride them at night, so they're in no way an uber replacement.
Also my city is meeting tomorrow to discuss banning them. The writing seems to be on the wall for all these scooter startups. If anyone knows a good vehicle for shorting these companies, let me know ;)