Those calculations explicitly do not include two kinds of costs that make the result that there's no positive benefit. You can't use that argument to reach that conclusion.

One of them is the cost of everything being in the wrong place. Humans have built farms, dams, ski resorts, cities, and all kinds of other things based on the current weather. If the Earth warms up, all of these things will be reduced in effectiveness.

The other is the cost of everyone being in the wrong place. When the water and food moves, the people who are the beneficiaries of the the climate change and now have surpluses of food and water and not going to donate to the people who now have shortages. Food and water will be on the other side of a border and political unrest and likely even wars will break out. People will starve. Crops will die.

It's not the argument that a warmer climate is good for the human race is incorrect. It's just that it only refutes the argument that a colder climate is somehow inherently bad or that the current climate is inherently perfect. It's only perfect because we've built ourselves and our world taking it into account.

Any change in climate is spectacularly bad for the human race. And that's very unfortunate because the only thing almost everyone does agree on is that the climate is going to change.