Increasing the framerate by rendering at a lower resolution + upscaling, or outright generation of extra frames has already been a thing for a few years now. NVidia calls it Deep Learning Super Sampling (DLSS)[1]. AMD's equivalent is called FSR[2].

[1] https://en.wikipedia.org/wiki/Deep_Learning_Super_Sampling

[2] https://en.wikipedia.org/wiki/GPUOpen#FidelityFX_Super_Resol...