How come is it a US only problem? Well, the way the problem is stated is US only, but everyone will need a new job to bring bread on their plate or pay other bills? Whether they live in the US or not. Is it not true?
You're not wrong - but healthcare is the concern here because it represents the risk of sudden, unexpected, and massive costs at the worst possible time. Whereas having to eat and pay rent/mortgage is a known and predictable cost we can plan and prepare for.
While the ACA filled a lot of gaps, it's still possible to find yourself without insurance and without any insurer who will take you on - or being unable to afford it (which is what unemployment tends to do to people...), especially if you're above the cut-off limits for state and federal aid.
As you know that is only one of the potential problems caused by unemployment. Pointing out a concrete, potential life-or-death problem gives more punch than just saying abstractly that there will be problems.
So the boring version: you will be left with the problem of a sudden loss of money as (concurrently) labor power vanes because LLMs don’t go on strike and you have no one to complain to since no one with any power has to care (see: LLMs don’t strike) that unemployed person #5468 today couldn’t pay their mortgage again and/or started on an opioid death-of-despair campaign.
You're getting hung up on an irrelevant detail and missing the point. The point is that one will still have bills to pay even after they don't have a job. That is not a US-only problem, that is a human existence problem.