Getting new hires up to speed is expensive enough that they'd be pretty stupid to actually do this. Sure a few do, but it isn't common.

Also, a couple minutes with google turns up this: https://stats.oecd.org/Index.aspx?DataSetCode=AVD_DUR . If it says what I think it says, getting a new job really is easier in the US (like it should be, because as any economist will tell you this is what has to happen when a bad hire is less of a disaster for the employer).

I think it boils down to whether you want to take care of yourself, or if you let the state do it for you.

In part, yes.

But also, there are two approaches to reducing downtime. You can increase MTBF (make things more reliable, make it harder to get fired); or you can reduce MTTR (make things easier to fix, make it easier to get hired somewhere new). Europe goes with the first approach, the US goes with the second (which I very much prefer, because it doesn't gum things up).

Separately, there's also making downtime less of a problem (failover systems, all the various other social safety net things). The US is generally known to kinda suck at this.