That depends entirely on the customer and how long they want to be hearing chainsaws, chippers and having trucks and equipment on their property. Can it be done with just one guy? Probably not reasonably, especially if you live somewhere like I do, the Pacific Northwest and the trees are big. But a few guys and a small operation with small trucks and minimal equipment? Sure, but they still need to be licensed and insured, they are doing a hazardous job, and with the time not being saved by machines you’re paying for significantly more labor hours. The reason tree trimming businesses do it that way is it’s generally more efficient and more efficient typically costs you about the same but puts a little money in their pocket. Things have a built in cost that you can’t undercut with out straight up losing money, you pay what you pay or you do it yourself (and you still have to pay some of that for the equipment or gear needed). Business works best at scale, that’s just how it works in most industries.