Truth is less important than pack mentality. With polarization, it matters that you’re showing you’re part of the in-group more than overall truthfulness. So a bell ringing when a lie is told probably wouldn’t help.
Politicians follow social media trends, because that gets them clicks. That causes showboating in Parliament, since they get to use CPAC clips to their followers. But they don’t tend to lead the trends.
MPs are under a lot of pressure to fundraise. Since union and corporate donations have been limited, MPs need to mobile their followers to send money. The best way to do that is with polarizing content on social media.
Outgoing Conservative leader Erin O’Toole said similar things in his final address to Parliament: MPs are chasing social media engagement, and that drives polarization.