> Giving money to a foundation (which they may or might not own) for greenwashing

What evidence would be required for you to believe that a donation to an environmental cause wasn't greenwashing?

Your list of exceptions seems fairly obviously aimed at making the task impossible because it's all based on interpretation of motives. You're essentially discounting all actions that have positive societal effects as long as doing so is motivated by money which is counter to the point I was making.

Giving money away to charity, by the meme interpretation of fiduciary duty, would be illegal. Instead, companies do it all the time because it makes them look better which might improve their business outlook in the future. That satisfies fiduciary dury despite it being a red line in the accounting books.

Wouldn't you like to live in a world where people care enough about doing good things that they'd prefer to patronize companies that do good things? That seems like an incredibly positive effect, regardless of the business' motives.