I think there is two important points that you haven't considered:

• Information asymmetry: in economics, this is the situation where one party has more/better information than the other. Of course a big corporation will have more information about a product I'm using that I would on every product I use, especially given that they can hire as many specialists as they want. Because of this, consumers should not be expected to take care of all societal change through their choices

• You seem to imply that these companies only exist to satisfy a customer need. While this is partially true, this completely omits the fact that since 15 years, every company has a marketing department, whose sole purpose is to suscit this need in the consumer mind. Company are not just need-fulfilling machines, but also self feeding systems. You can't talk about the fact that renewing your phone emits a lot of carbon without talking about the fact that every phone company spends millions at making you want to renew it