>>First of all, your words are saying outsource, not mine
Maybe you have a different definition of outsource, then. For me, outsourcing is not necessarily sending work to a cheaper worker.
>>If you hire talented folks and understand how to divide labor properly
Sure, but I don't think this is about division of labour. It's about communication, the small talk, all the things you have to hold in your head and cannot communicate because there's too many of it, and it's changing constantly.
I've worked in startups where it was thought possible to bring together a random group of people and get work done, and it failed miserably. I've also worked in startups where we did not do it, and went ahead to be successful. These are subjective experiences, but after almost two decades in software, I can humbly say I can see the patterns.
>>Saying that you should hire the minimum amount of people to do the entire workload without taxing the finite biological constraints of the human body
You should hire if you can, but it may not always work out if the person is remote and the role demands a lot of face to face interaction.