This assumes tech giants aren't the giant colluding monopolies that they are, and actually need to be competitive in quality or price to survive. The tax will be payed by consumers, and shareholders aren't going to see a difference in their dividends.
Picture this: all tax for the budget collected from pollution taxes, so: zero sales tax, zero wage tax, zero home owner taxes.
What do you think society will optimize in that case?
Yet currently we tax on labour and on home ownership, but not on Amazon. Look around an see the result.