Why were even Zuckerberg and Dorsey there? It seems like it should be a debate within the senate - they clearly cannot do anything but complain, whatever FB/Twi

Why were even Zuckerberg and Dorsey there? It seems like it should be a debate within the senate - they clearly cannot do anything but complain, whatever FB/Twitter does. They'd need to agree between themselves on something first, then they can talk to the social media companies (who were now just in a useless crossfire).