When social media becomes the primary driver of misinformation and anti-democratic sentiment, then it has arguably “stopped working”. While users might not be sick in the flesh, their minds will surely start to rot.
The platforms aren't the problem, people are the problem. Education is piss poor, if that's not fixed/improved, we can go back to pre-industrial times and people would still vote for a moron who promises big things, never delivers and just grabs power for themselves.
Financial/civic/political education in schools? Public-sponsored articles and videos debunking conspiracies? Nah, just ban Twitter, that'll solve it.
People on either side of the fence believe they're right. Keep ignoring and belittling each other and it will lead to an even worse situation down the road.
Are blocked sewer is a people problem; it’s either poorly designed, poorly constructed, poorly maintained or a combination of causes. But in the end, the problem is caused by people.