They’re not doing that. They have different ways of tracking you and don’t need to listen to your real-life conversations, because they all (hopefully) know that if they were caught doing that, people would actually (hopefully) be upset enough to demand reform.
Take for example your location data. Is Google storing your location data? Yes. Are they selling it? I doubt it. Instead, big companies at one point were able to track your movement within stores by using your bluetooth beacon address. IDK if that’s still possible, but that’s more in line with the way these things pan out. Also keep in mind some companies have incentives to keep data to themselves, usually when said company peddles ads themselves. You’re still being tracked and are the victim of targeted advertisement, but your data is more siloed than you think.