I imagine banked money isn't taxed, but any spent would be, so every expenditure shoots up a bonus 20-40% relative to the value of just leaving it alone. Which means any revenue has to match, and exceed, the tax to actually be profitable (versus sitting on it)

Same way, I think, apple keeps $800bn unspent; not spending is simply more profitable than spending

And i guess at that level of money, its generally not worth doing much unless its big (due to all the overhead necessary to keep such funds available and tracked).