If I had a nickel for every time a full power cycle fixed it all, I’d be rich. However, if you did power cycle before and call in again, often it’s an issue that needs deeper investigation. In that case, the tech can likely watch the process of your equipment coming online in realtime to see where the issue is happening. Network entry, authentication, package application, DHCP, it can often be monitored as it’s happening. A reboot while on the phone starts the process right from the beginning so it can be monitored to determine what happens immediately and what happens after it sits for a while.

I work in tech support. An error I haven't seen doesn't exist. So yes, I'm going to re-trace the trouble-shooting steps with you.
90% of the people who call in haven't done it, but claim they did. Because they think I have a magic tech wand that can find and fix all problems, and that I just make them go through the motions because I'm lazy.