This eurogamer article was from September 2017, so I don't know if the situation has improved much since then but I doubt it.
"Normal mode, runs at 720p on Pro (yes, really) and a blurry 640p on base (this is an approximate measurement: the game is so blurry, pixel-counting is very difficult) while the detail mode offers up 720p on the standard PS4 and 1080p on Pro."
"Base PlayStation 4 performance overall just isn't good enough. Whether you're playing in normal or detail mode, detailed jungle scenes drop well below 30fps. For a 720p title, let alone a circa 640p game, it's actually quite remarkable to see performance drop so low"
I don't have high hopes for docked when it can struggle to hit 640p30fps on the PS4, never mind handheld mode. "Visually comparable" to PS4/Xbox? I'll believe that when I see it.
I think its more about how bad they are at optimising, than how demanding the game actually is.
So maybe they put more effort into getting it to run on the switch, it might run better there.
However that video they released, Im pretty sure is sub20 fps, and it has micro stutter.
Its probably a early build, but like I said.... no faith at all in ARK developers.