If you are working on a project at your home, it is great to be able to have lumber cut to size in Manhattan. Many residents of this city do not have the room to use power tools because they live in small apartments. This means that they do not have a yard or a garage where they can use these tools or store them. Aside from that, making that kind of noise in an apartment or in a city neighbourhood would probably draw a noise complaint from a neighbor or two. At that rate, you would never get anything done and it would be completely frustrating.
Most people who just need to get a small project done only need one or two pieces of lumber and if they can get that lumber cut to size in Manhattan then they are good to go. They can return home with all of the pieces of lumber that they need, cut in advance, and ready to take on their project and complete it without any issues. All you will need is to show up at the hardware store with the measurements of what you need cut. The lumber can then be cut on the spot while you wait or you can return later in the day after purchasing the lumber.
When you work on a project that involves more than an item that needs assembly, it means that you are building something from scratch and you need to have lumber cut to a specific size. Cutting lumber with precision requires some expensive equipment that must be calibrated properly. If something is out of alignment or you do not know how to cut lumber, the piece that results after it has been cut may not suit your purposes. This would be not only a waste of your time, but a complete waste of money. It is a much easier process to attend at a local hardware store, purchase your required lumber and then have it cut for you.