Will subcision be successful for deep acne scars? (photo)

I am not at all surprised by your lack of success with fraxel lasers, since the hard science to back up their use lags well behind the heavy marketing hype and social media buzz to hawk these expensive "bells and whistles " gizmos, as you unfortunately found out the hard way. Sorry.
Nor am I surprised by the lack of success with microneedling, since this technique is best reserved for treated superficial, surface color and texture issues. And if RF microneedling was performed, this simply added to the expense and potential risks. Once again sorry.
I have personally been performing subcision for elevating and smoothing all kinds of indented scars, including deep acne scars, for thirty years with very gratifying results. The cheeks here show significant generalized, scar-related atrophy, so I would first consider a Field Subcision in order to elevate and smooth the overall cheeks, followed by individual subcisions as needed.
I stopped using fat injections many years ago for a number of reasons. Number one, despite the hype about permanent results, the fact is that much of the transplanted fat, separated from its original blood supply, does not survive. Secondly, it is a two-step procedure using large bore cannulas (after all fat is thick), to remove the fat from the donor area and then to inject it into the recipient area, which leads to lots of trauma and significant and often prolonged, post-treatment swelling and bruising. Thirdly, any fat that does survive retains the characteristics of the area from which it was taken, such as from the belly. This means when, with aging, the belly fat develops a "love handle," the belly fat in the face is likely to do so, as well.
You would be wise to make sure to be consulting with an experienced, board certified cosmetic dermatologist subcision specialist, which, as a rule is difficult to find these days, since so many venues are into hawking the expensive light and energy-based, "next big thing" gizmos. Hope this helps and best of luck.