Gone In 60 Seconds

Because not all of us sit at a desk all day, and it’s a lot easier to bring a phone in your pocket than a PC?

That and my phone screen isn’t exactly “tiny”
You don't need to sit at a desk all day to own a PC.
And compared to a monitor, even the earliest ones made, your phone screen is tiny.
Also, I'm not tethered to my phone like some people seem to be in this world, spending 3/4 of their awake time squinting into it..