Why don't more surgeons do fat-fascia grafts to correct volume loss in the face, given the reabsorption rate of injected fat?

LiveFill grafts do not consist of dermis, only fat and fascia. The dermal fat (fascial) grafts did not succeed because of the lack of pliability of the dermal layer and large clumpiness of the grafts that didn't allow sufficient time to revascularize before they died. The blood supply didn't have enough time to revascularize the grafts before they died due to a poor surface area to volume ratio. LiveFill overcame the surface area problem and the lack of pliability problem of dermal fat grafts. It isn't rocket science, it's just biology. All surgeons learned that you don't put a really thick skin graft on a wound because it won't survive, but surgeons forget that the same principles apply for tissues below the surface, and wonder why a fist- sized fat injection graft doesn't survive.

While it is true that dermal-fat grafts can have better survival than injected fat grafts, they do require a donor site harvest and a resultant scar. This is an aesthetic issue that larger than the dermal-fat grafts becomes not to mention the need for an incision to place the graft.

It's all about the comfort factor and what works for a given surgeon. I think that most have more experience using fat grafting.   I have used fascia for lip augmentation and rhinoplasty.

fascia has almost no volume, it is very thin and you need to make big dissections to get it out. The addition of fascia has not shown to be better in longevity.  If something really works, everyone does it.