Ultimately profits flow to a single entity. Taxing 1 levels down and stopping was clearly not the intent of my suggestion. If it’s under the control of Alphabet/ its profits go to Alphabet treat it as a single entity Alphabet.
The idea that subsidiaries, trusts, etc have any meaning whatsoever when collecting taxes is simply a loophole which can be closed at any time.
And for every regulatory change will bring changes to tax avoidance... subsidiaries will just get "one more step" removed from the main company...