It likely isn't even 1080, the Switch itself is 720 and games MAY upscale to 1080p when docked, but that will affect performance as well.
The Switch was underpowered at launch, but that kept it affordable I guess. I hope they do a revision, they tried that with the "New Nintendo 2/3DS" but I don't believe that was very successful - only a handful of games came out targeting the hardware refresh. No games company wanted to leave the millions of regular 2/3DS consoles behind.