Some games are great on a handheld and a console. For instance I can play Pac Man on a big 54 inch tv and still enjoy it as much as on a portable. However some games do not fit on both. Animal Crossing is best on a portable. A huge cinematic game is best on the console.
The Switch has games that are good at being a portable game and a home console game. Also the Switch does both so it can be whatever you want it to be. Like a Ditto.