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.
But neither is a realistic outcome. And neither do you personally have anything remotely near “control”. The reason everyone argues about this stuff online is that’s literally the only power we have.
However, the same effort and energy spent elsewhere can reap much, much bigger dividends down the line.
So are big corporations.
Only one gives users any kind of democratic influence over policy.
And voting does make a difference. Ask New York.
But Congress won't fire Trump. All of my representatives would, if given a chance, but other representatives in other districts have no accountability to me and don't want to.
So I'm not sure how to avoid the conclusion that I have less practical control over the federal government than I do Google, even if the formal levers of power are meant to achieve a different result.