While it is good that
some developers have written an abstraction wrapper so they can largely do the same thing whether the upscaler is DLSS/FSR/XeSS, we are mainly talking about Bethesda here, right?
Because Bethesda shipped Skyrim with only a x87 codepath. In 2011. When SSE and had been in use for over decade!
Plenty of threads about it at the time like:
https://forums.guru3d.com/threads/b...cpu-optimization-of-the-decade-gaming.356110/
Now, Bethesda's coding prowess in the past is no guarantee of releasing unpolished this time,
and even if their coding is still sub-par this that wouldn't preclude any shady hidden deals with AMD which exclude DLSS (we certainly know the green team have done plenty of those in the past, but with AMD's dGPU marketshare almost in single figures sabotaging DLSS is hardly going to win them any favours).
However, it is equally possible that Bethesda's engine coders are not the kind who would even consider writing an abstraction wrapper to make their lives easier. Whereas a studio only going ports like Nixxes are far more likely to do so.
While FSR may be poor imitation of DLSS, it does work on the consoles, Radeon, GTX and RTX. No matter how much people like to moan about it, unless Nvidia change tactics DLSS is likely to end up like G-Sync vs FreeSync.
IMO, it should be Nvidia swallowing their pride and writing an open-source abstraction layer so that switching from DLSS/FSR/XeSS really is as simple as one config line.