You can do sensible (but still delightful things) like get the developer console (where your console.logs go, and where you can evaluate js expressions in the context of the webpage) you expect on your normal computer, but operating against a webpage on the mobile device.
BUT ALSO you can set up port forwarding so, say, localhost:8080 on mobile maps to whatever's on port 1234 on your laptop.
AND ALSO ALSO you can screencast the page content mobile device into your laptop, so you can save your neck muscles from looking back and forth at two screens.
Wait no not silly at all since you get the integration with mousing over dom elements and getting highlights of the actual elements and vice-versa. Super useful stuff.