These companies are monopolies, they can’t be significantly materially affected by a consumer boycott. Most of their customers are in industry anyways. Any boycott against them is more about raising awareness than achieving something, it’s a diffuse form of political education.

To take on the fossil fuel industry requires having control over big levers at the top of the economy. Those levers are currently pulled, anarchically, by capital, not actual humans. Capital pulls those levers and spurns its highest level servants to get out of the way or feed it more bodies. To end this society-wide violence we must displace capital, it must not be in charge. We must be in charge.