True in a mathematical sense but irrelevant in practice. Realistically there won't ever be enough firefighters available nearby to cut an effective fire break around an entire town while a wildfire is burning nearby. Do you have any concept of how much manual labor and heavy machinery this takes?
That's one of those hilarious "peak Hacker News" comments from someone who obviously has never spent much time cutting down trees and clearing brush. There are hundreds towns at risk of wildfires. The scale of effort necessary to cut effective fire breaks around them and keep them clear every summer would be enormous. The state has nowhere near the budget for that. Do the math. And besides that there are numerous other problems including private property access and environmental impact laws that make the whole idea ludicrous to anyone who lives in the real world.
You know firebreaks can be cut before a fire, right?
Even in the case of an emergency firebreak, if there aren't enough firefighters to cut one large one, there aren't enough firefighters to cut lots of small ones with a greater total length.