For some people that could be an option. For me it is not. I travel a lot usually on the weekends and if a customer or my main work calls me with an issue I can login to their machine(s) with my smartphone and fix the issues on the spot, instead of them waiting till I can get back home to my computer.
I have fixed many computer server issues from my phone, resulting in the customer or my work being happy that I resolved the issue so quickly and I do not have to worry about rushing home to fix the issue.
If you are wondering what I use, the program is called Teamviewer. For some other clients I also use a VPN and remote desktop in. All of these are apps I can have on my smartphone.
The only issues I cannot fix remotely of course is hardware issues. But for the most part I am able to fix the issue from where ever I am.
Now if I have no cell signal or a weak cell signal from my carrier (AT&T), I have a Verizon Hotspot that I also use that gives me unlimted internet access from where I can get a Verizon Cell signal.
I use my phone for more than just playing Candy Crush