> The uniquely American idea that you can be fired at any time for any reason is for me utterly terrifying

As an American nearing the end of a decades-long pretty successful tech career maybe I can offer some useful perspective. Having spent quite a bit of time interacting with international colleagues one difference I've noticed is that American high tech workers are more aware of and connected to their employer's bottom line. This is partly because stock options, RSUs, profit sharing, performance bonuses, and commissions tend to be a more significant portion of our overall compensation here. But a more meta reason is that generally speaking, companies are both started and go out of business faster and more often here. The faster pace of the overall economy leads to less effective firms reaching the natural consequences of poor performance faster.

I haven't looked up the data but I suspect the average length of employment of highly-experienced skilled employees is shorter here. It's not just due to being laid-off from a failing or pivoting firm but also because employees choose to leave for other opportunities more often. I've had international friends assume "perhaps you Americans feel less loyalty to your employer or employees" but it's more that loyalty is earned (and lost) faster.

While different firms and industries vary, I think there's an overall trend from employees of "switch employers faster" which is matched by employers tending to hire and fire faster. In my experience, this also seems true for other job changes like promotions and employees voluntarily applying for open positions within the same organization (against their direct manager's desire to keep them). On those anonymous employee satisfaction surveys run by HR depts, there's often a question asking employees to rank "How likely is it you'll still work at this company in X years". I'm pretty sure in the U.S. those responses average much shorter than in Europe. So, while there's a higher level of medium-term job uncertainty, it's just the necessary 'other side of the coin' of having a higher level of medium-term upward mobility.

For me, none of this feels 'scary'. Frankly, I wouldn't want an employer to be required to keep me around for one minute longer than makes business sense for them. The reason is that for most of my career, my performance stock options and bonuses have consistently increased, often to more than half my total compensation - sometimes much more than half. To be clear, that extra money wasn't a "gift" or granted because the company is "nice" (though nearly all my employers have been very nice). They keep increasing my comp because my market value is increasing and they are justifiably worried I'll leave for a higher paying or more interesting job elsewhere (or to do my own startup). When it comes to highly skilled workers at silicon valley tech companies, managers often don't even have to fire employees who aren't performing well. Once the employee sees the performance part of their compensation falling to match their current value to the firm, the employee will quit to go somewhere that values them more.

My relationship with employers is similar to how I feel about my relationships with romantic partners (and now my spouse). There's a constructive tension that makes it work. I want to continue being in the relationship not because "it's comfortable" or, worse, "this person is about as good as I can expect to do" (ugh!) but rather because I so highly value the other person I'm worried she'll 'come to her senses' and dump me for someone better. I think an ideal relationship is where both parties feel that way equally. I want to be so valuable to my employer that they're worried I'll 'come to my senses' and quit. Conversely, I want the job I'm in to be so well-suited to my skills, challenging, enjoyable and highly-paid that I'm worried they'll 'come to their senses' and replace me with someone better or cheaper. If either party ever stops feeling that way, the relationship is ultimately going to degrade anyway and life's too short to remain in relationships where the value dynamic is unbalanced for any significant period of time.