That's an acceptable view point. However, that doesn't mean FB should not be punished into oblivion. They don't get a free pass just because "someone else would have done it if we didn't" is not an acceptable defense.
Instagram, TikTok, Snapchat, Reddit and Pinterest each have more MAUs than Twitter [1].
[1] https://www.searchenginejournal.com/social-media/biggest-soc...
Facebook is the biggest. And we have evidence of the harm it, specifically, causes, in a way we don't for its competitors. They also have a spectacular track record of lying and lawbreaking.
Just to reiterate, it's not that it is "just" harmful. They are actively studying how to make it even more so.