Social media is a bad feelings machine. Why can’t we just turn it off for good?

Ihave a fantasy and it goes like this: a political party is formed, running on an anti-social-media platform. It campaigns on a pledge to ban social media. (“SWITCH IT OFF” is its straightforward, and elegant, slogan.)

The party wins a general election and at midnight, on what comes to be known as Social Media Freedom Day, the prime minister pushes a giant button that blocks all access to social media. Crowds cheer. On the anniversary of Social Media Freedom Day – which becomes a bank holiday, of course – children...