Team / interpersonal communication overhead, planning overhead, and dealing with less skilled members of the team can easily make 4 engineers roughly as product

Team / interpersonal communication overhead, planning overhead, and dealing with less skilled members of the team can easily make 4 engineers roughly as productive as one very skilled engineer, just at 4-5x the cost once you include the increase in product/project management required by multiple people. We tolerate this generally because eg upskilling peers is important to scale a company, but pre-PMF it's a huge advantage to have just the one outstanding engineer.