That's quite a broad generalization. For sure a lot of the biggest names have done ethically questionable things. It's no doubt that growing that fast and gaining that much power is going to hugely amplify whatever ethical flaws the founders have. And no one is ethically perfect. That's not to excuse Uber, Facebook, Google, Amazon or any of the more egregious companies.
But it's just a case of confirmation bias if you didn't look for counter-examples to try to disprove your theory.
Are the following companies ethically perfect? I doubt it. But I haven't heard much bad about them and they have changed my life for the better significantly: AirBnb, Dropbox, Stripe, Rappi, WhatsApp, Square, Netflix. I bet I could find others.
