I will welcome corrections but i recall reading that for large profitable firms the effective tax rate is already well under 10%.
For a select few, perhaps, but for the average of US-based large-cap firms, 10% is not even close.
In the drug/biotech industry, the income-tax rate for the parent company (which pays a mix of country-specific rates) is typically between 20% and 30%.
“The efficient-market hypothesis may be the foremost piece of B.S. ever promulgated in any area of human knowledge!”