iPhone ios15.5 - “other data” will not delete after factory reset

I iPhone storage is full. I tried numerous methods of deleting apps, caches, photos and videos without success. I then backed up my phone to my Mac. I factory reset the phone. When setting up the phone from factory reset I did not use the back up on my Mac as I wanted to see that the “other data” was actually deleted from the phone. It was NOT. Now my entire phones memory (except IOS) is full with “other data” - it actually grew in size after the factory reset?? I’m super confused. Please can you provide some assistance? Thanks