I think you're missing the point. As companies grow they tend to expand into other lines of business, which obviously requires additional resources. But if a software business is structured properly then revenue will trend upward at a rate which increasing diverges from labor costs. That's literally the whole point of automation. Draw a chart of revenue per employee for Google from when they were founded until now.

Labor isn't necessarily entitled to any particular share of revenue. Employees get whatever they can negotiate based on market rates at the time. And those rates are based far more on local area and industry demand than on the current revenue at any single company.