Tax incentives these days include transferable tax credits. Even if your net tax rate was 0%, you can sell the credit to someone else, typically a bank. IOW, states and countries give you money, not simply give you a tax rate break.

Hollywood accounting rules are regular accounting rules (GAAP). The only reason “Hollywood accounting” is a thing is because of a bunch of actors who didn’t know the difference between “gross” and “net” points got screwed over.

Everyone involved still pays their taxes, but the special purpose vehicle used to organize the production is essentially a passthrough entity.