1 small guy changing stuff is basically impossible. But 100 million small folk sufficiently annoyed with something changes a government (for better and for worse), whilst having basically zero influence over a corporation (they're not the customer, they don't have enough buying power for a hostile takeover, they certainly don't have the wherewithal to destroy them by launching a competitor... which they probably don't even want to if they think what the corporation does is bad). The exception, of course, is that if the corporation bothers that many small people that much, a government might get around to listening to the small people's arguments more than the corporation's.
> But 100 million small folk sufficiently annoyed with something changes a government (for better and for worse), whilst having basically zero influence over a corporation
They don't have influence because you designed them to be so. You said they're not the customer and implied they have no influence over customers.
Your argument says 100 million small folk in the same government jurisdiction have more government say vs 100 million small folk have in a company they have nothing to do with. That seems clear.
The inverse relation could also be said though. 100 million small folk in different government jurisdictions have less say in a government they have nothing to do with than 100 million customers of the same company do with a corporation.