I recently bought an adjustable clip to clip the Switch (sans joycons) to my Pro Controller and it’s super comfy for long periods of gaming. I’ve also seen people use 3rd party joycons that are shaped more like the Pro Controller handles which seem comfy too.
You’re right, the base Switch isn’t all that comfy for long periods of play, but there are both ways around that and it can also be played docked, which I think are redeeming features.