If I grow $1000 worth of corn. Who did I exploit? That value did not exist before I grew my crop.
If you grew it yourself, no one. But you miss a point: that $1000 already existed, you exchanged value (of something you worked for) of useful product (food) for unit of trade.
Did what exist? Wealth? Food? Wealth is something that is useful, and most of it needs work (food grows on it own) but needs work to plant, water, harvest, distribute etc.
So billion dollars companies managed to exploit workers because they had a useful product. Product they traded for money. Product bought by those exploited workers...
And who built those products? The owners? the CEOs? Don't be an idiot, this is such simple logic to understand, yet for some reason you either don't see it or play dumb.