No, because that is something that has to be separately carried, plugged in, and requires additional table/desk space. In my experience, there's not room for an external mouse on the fold-down tables of an airplane or train.
Also, when I take video calls at home, I'm usually in my bedroom for noise/privacy reasons. I don't have a desk in there, so I'm on my bed. There'd be nowhere to use a mouse.
Examples like this abound. Like, what if you're using a laptop on a sofa or recliner? What if you're at a cafe and table space is at a premium, or you don't want to put your mouse down on a dirty table?
Is this much explanation really necessary? If an external mouse were really the solution to all my problems, why wouldn't I just be using one?