It isn’t really the same thing.
The wii u gamepad did not provide much extra value to games while playing on the TV. It was basically a token add on to all of the games i played, moving UI elements that would have worked better on the TV to the gamepad just to use it. As a controller, the wii u gamepad was a failure.
Whether you think it allowed you to remotely play without using the TV to a decent quality of life is separate. I’d argue that the switch is just a mobile device with an HDMI out.