Basically, the Dunning/Kruger effect breaks down to this: Since you don't know what you need to know to perform a skilled task, all those little nuances of technique and safe practices, you tend to think that the activity is easier than it really is.
However, the worst that happens when you try to make Grandma's cookies is that you might end up with a batch of blackened cookies. You're out ten bucks on sugar, flour, and chocolate chips. No big deal. Things are a little different when it comes to wood floor refinishing. A service might be the way to go, and here's why.
First of all, like Grandma, a wood floor refinishing service has done this a thousand times. They know what tools are needed, they have mastered the nuances of technique. All of the little craftsman's touches that you might take for granted, until you try to recreate them. Will your floor be as lustrous? Will it be as even? Will the color be as rich? If the Dunning/Kruger effect has anything to say about it, it's a safe bet that they won't be.
Second, and probably most important, a hardwood floor refinishing service knows how to do the job safely. There is a lot that can go catastrophically, dangerously wrong in a floor refinishing project. It is a job that requires large, powerful tools that can not only damage the floor if not controlled properly, but can also inflict dangerous injuries to a person’s body. Nobody wants to gouge their floors, because they pressed a teensy bit too much on the sander, and they really don't want to let a runaway saw tear up their house. A trip to the hospital is straight out of the question...
In the end, whether you choose to do your floors yourself or not, is up to you. Just remember that if you go to Grandma for amazing cookies, you will get amazing cookies every time. If you come to Delair's Carpet Barn in East Montpelier, Vermont for wood floor refinishing service, you get amazing floors!