DLSS works great for those with very expensive NVIDIA graphics cards that can make use of it.
However this represents a minority of NVIDIA graphics card owners nevermind a small minority of overall graphics card owners.
FSR has been implemented because it works on the vast majority of hardware from NVIDIA and AMD and will also work with the new INTEL graphics cards coming out next year.
Coincidentally INTEL is bringing out their own version of DLSS called Xess which works like DLSS in that it utilises deep learning, but it is platform agnostic so should work with the majority of NVIDIA, AMD and all upcoming INTEL cards.
I would therefore Frontier to adopt this technology than the walled garden that is DLSS.