This is the kind of thing that kind of makes some of those initial Switch ads kind of cringe in retrospect; yeah, it's more convenient to just prop it up and play it at the park, but if you were at the park to begin with...wouldn't you be taking in the scenery, walking, maybe even jogging to workout, or whatever? Not playing your Switch outside just because!
I have a NUC on order that I'll hopefully be getting sooner rather than later from Simply NUC, and I'm hoping that one can use a portable battery with it plus a portable monitor for a reasonable amount of time and can experience the full power of a desktop without the compromises of a laptop. Then again, it has a RTX 2060 for discrete graphics, so IDK how much it'll actually be able to pull off on that kind of setup.l