> From a legal point of view at-will employment seems like the default when it comes to buying a service (ie. labor).

I think this gets to the heart of the difference: Americans tend to think of their employment as a continuous exchange of dollars for their labor, whereas most of the world takes the concept of an employment contract to heart.

That contract, in turn, contains both legal and contractual stipulations that prevent firing without cause: employers must give you so-and-so many weeks of notice before beginning the process of firing you, must pay you for so-and-so many months if you present an argument to a labor board, &c. There's nothing informal about it: it's the difference between continuous billing for a service and a fixed-length contract.

Here's a random PDF I found that explains some of the difference between US and French labor contracts[1].

[1]: https://www.bakermckenzie.com/-/media/files/insight/publicat...

This will depend on your views on politics/society/humanity. I know that there one side of the argument that workers should be basically hot-swappable and rack-mountable. I am often a bleeding-heart liberal and am pretty far to the other side of things. Underneath everything here it's more a question of feelings and values more than any sort of logic. Different countries' laws may come down on different sides of the argument here.

A virtualized server from Amazon does not need food, clothing, and shelter to survive. It does not have a family to support. Simply, it is not alive. and laws around humans and commodities should probably be very different.

More cold-hearted practical arguments for businesses: the virtual machine cannot vote in the next election, it cannot contact the local news media to complain about working conditions, it cannot unionize. If things get very bad it cannot buy torches and pitchforks.

Employing someone in most of the world is not seen as simply buying a service. It's not a subscription. Are you aware of the concept of Noblesse Oblige[1]? As the worker is smaller and more fragile the business can handle the burden better. The business has lots of employees whereas the employees have only one employer.

[1] https://en.wikipedia.org/wiki/Noblesse_oblige

But do they also control your healthcare?

Your boss does.

Not in the big majority of developed countries... The US is also the big exception in that.

That is precisely my point.