Upsampling in Spider-Man Remastered has great optical advantages over rendering in identical resolution with classic TAA, regardless of whether Nvidia's DLSS or AMD's FSR is used: So before reducing the resolution, it should be set to DLSS or FSR.
DLSS is qualitatively ahead of FSR on several fronts, but of all things the raytracing reflections flicker massively with Nvidia's AI upsampling, which is virtually not the case with AMD's FSR 2.0. If that bothers you even slightly, you'll be better off with FSR 2.0, despite other disadvantages.
If the graphics card does not support DLSS, you will find a much better partner in FSR 2.0 than in the game's own IGTI. Although the latter brings more performance, it cannot keep up in terms of quality in every respect. In the end, the native game mode including TAA is visually the best with the same target resolution, even if it offers a noticeably slower performance. This time, for various reasons, DLSS and FSR do not quite come close to this, but they do offer significantly more FPS.
Nvidia's DLSS algorithm can also be used in the game in the form of DLAA without fewer render pixels. In terms of image sharpness and image stability, DLAA offers advantages over the native resolution and does not cost a lot of FPS at 5 percent. However, there is also the ant effect with DLAA as render pixels in Ultra HD and in WQHD it is so pronounced that the use of the technology does not seem sensible.