I don't own a daycare but I used to work in one a few years ago.
Although the parents brought their own diapers we found that the Pampers Baby Dry or other Pampers as well as Huggies diapers were the best diapers to use.
Pampers and Huggies are good diapers and they absorb a lot more and are prone to less leakage than other cheaper brand diapers.
However the parents are the ones that actually provide the diapers so they would be bringing whatever diapers they would buy.
Sometimes some parents would use pampers or Huggies at home but then buy the cheaper diapers for daycare.