I usually mention and explain the Fediverse and the many already existent platforms to anyone who starts complaining about the current state of social media. And explain why it would be better for the world for us all to move into a decentralised network than a corporate owned infrastructure.

As for Lemmy, most people were never on reddit. In my social experience, very few people ever used it. But the ones that used and use reddit, absolutely lemmy came into the conversation. And older tech nerds become immediately interested. As they should.