2) Even with evil companies, contributing doesn't always mean helping evil. Companies are, as you pointed out, abstractions. I find much of what Facebook / Meta does to be particularly evil, but they have some very good, ethical projects I'd gladly work on or contribute to.
3) Even so, if an organization were evil, there are different tactics. Microsoft isn't going away. One can affect change from the outside or from the inside. In many cases, the best way to turn evil into good is to engage and contribute.