Most work is redundant and unnecessary. Take for example the classic gas station on every corner situation that often emerges. This turf war between gas providers (or their franchisees by proxy they granted a license to this location for) is not because three or four gas stations are operating at maximum capacity. No, this is 3 or 4 fisherman with a line in the river, made possible solely because inputs (real estate, gas, labor, merchandise) are cheap enough where the gas station need not ever run even close to capacity and still return a profit for the fisherman.
Who benefits from the situation? You or I who don’t have to make a u turn to get gas at this intersection, perhaps, but that is not much benefit in comparison for the opportunity cost of not having 3 prime corner lots squandered on the same single use. The clerk at the gas station for having a job available? Perhaps although maybe their labor in aggregate would have been employed in other less redundant uses that could benefit out society otherwise than selling smokes and putting $20 on 4 at 3am. The real beneficiary of this entire arrangement is the fisherman, the owner or shareholder who ultimately skims from all the pots thanks to having what is effectively a modern version of a plantation sharecropper, spending all their money in the company store and on company housing with a fig leaf of being able to choose from any number of minimum wage jobs, spend their wages in any number of national chain stores, and rent any number of increasingly investor owned property. Quite literally all owned by the same shareholders when you consider how people diversify their investments into these multiple sectors.
We benefit because when there’s only one gas station, they can charge more than if there are four.