Is the overall automation threat. Google it, 70% of middle class jobs lost since the 1980s got taken by automation.
It is very possible, even likely, that we are approaching a tipping point. You can find articles explaining that the baby boomers are the only ones who have any discretionary spending whatsoever and they are propping up multiple industries. They aren't going to leave anything for their kids either. They're spending it all. But they don't blow on RVs and mimosas they blow on healthcare at least in America. And even if by some miracle there it would have been some money left in there savings it looks like the trillionaire class is going to loot it. Remember that a lot of their savings is in the form of stocks because that's how they keep them above inflation and rules have been changed that will allow companies to take worthless stock like SpaceX and dump it into 401ks...
So all of this means that a relatively small amount of permanent unemployment might cause a cascading effect.
Simply put there won't be enough money in the economy. Too much of it at the top. The tax base collapses because people don't make enough money to pay taxes and yeah you can use tariffs to raise their taxes but then they have to spend less. Before you know it government spending collapses which causes even more job losses and therefore even less economic activity and spending. It becomes a self-reinforcing loop. The whole system collapses. Mix in declining birth rates and yeah it's a disaster that we just pretending isn't happening
The real fun comes when basic services start getting cut. Education goes away and you have kids just kind of wandering the streets with no jobs because even if you bring back child labor there's nothing for those kids to do. And then the police go. A bunch of numbnuts think that's cool cuz they are looking forward to being able to shoot people. Without realizing what it was like to have roving bands of bandits...
I don't think folks have really come to terms with how fragile our civilization really is.