Iirc, the Matrix demo with TSR turned off rendered in (native) sub 720p on Series S (vs 1620p and much higher settings on PS5 and Series X. That's like 5x Series S's resolution). Lumen, Nanite, Virtual Shadow Maps and crowd density were all dialed back on Series S. Unless whatever Epic did is heavy on the CPU, I just don't see what's so unrealistic or surprising about Switch 2 running the demo at even lower settings and native resolutions.
With some sacrifices, the Switch 2 could run the demo even at half the power of Series S. I wouldn't read much into people saying it's "comparable" to PS5/Series X's performance. I bet they think Series S version was also comparable (it isn't). Diminishing returns are just making the average gamer have the perception of a non-gamer grandma, and PS5/Series X's power being wasted on resolutions is also helping Series S and even last gen consoles hold their own when not compared side by side on a high resolution display.
