champagne activist
Champagne activist (noun): A person who publicly expresses support for a cause or movement, typically by raising a glass of champagne or making a toast, but who does not take any meaningful or sustained action to advance the cause. Also known as Slackatism.
"After toasting to the latest social justice cause with a glass of bubbly, the champagne activist promptly returned to their privileged bubble without doing anything to address the root issues."