Do you really trust the author of that extension with god-mode access to the internals of your browser? What about the buyer to whom they sell the extension be

Do you really trust the author of that extension with god-mode access to the internals of your browser? What about the buyer to whom they sell the extension because they're tired of maintaining it and they got a good offer? And why are they able to make such good offers to buy extensions that have a large installed base? Follow the money. And the data.