Are There Benefits to Having Fillers As Early As 28 Years Old?

No matter what your age, if you are aging poorly, then fillers can help a lot. Many patients in their 20's are on Botox and various fillers and look great and feel better about themselves for doing it. It is a good confidence builder if you look the way you want to. 

The likelihood of getting a good result with an injectable filler treatment depends more on your doctor than your age. You should consult a board-certified dermatologist or facial plastic surgeon experienced in the proper application of injectable fillers. You should also see many photos before you proceed.
I hope this is helpful for you.

Facial wrinkles are quite individual and often depend on skeletal structure, facial mannerisms and sleep patterns. There is no age that is too early to modify the appearance, and earlier treatment stimulates collagen synthesis which may help to prevent worsening over time. Seek a skilled board certified specialist to do it.

All of us age differently and at different rates. I am not sure what mixed reviews you are referring to involving fillers but the current fillers available to us have tremendously expanded our abilities to turn back the hands of time.
Many of my patients are in their mid 20's and their results are every bit as good if not better than in older women. The key to obtaining a good results with filler is proper diagnosis, prioritizing of goals, selection of the proper fillers for each wrinkle and picking a qualified Plastic surgeon or Dermatologist to do your treatment.