LAPTOP REPLACEMENT:

As long as Raspberry pis are small enough and power efficient, they can be carried around. A nice product that can act as an input/output interface to the raspberry pi looking like a laptop is the so-called lapdock. A famous one is Nexdock

As you can see, the first image shows a normal looking clamshell laptop, but actually in the second picture there an attached Raspberry pi 4 on the back of the screen along with a stick sized x86 PC with an HDMI hub to switch between them and the 'laptop' is actually a screen with battery, speakers, keyboard and mouse peripherals to display the output and receive input of them respectively.