>it's dehumanizing when you're hired to do something entirely different. Treating people as interchangeable units of labor is pretty much a textbook example of dehumanization in my opinion; we're not cogs who should be freely reassigned by authorities based on their whims, but individuals deserving of some semblance of autonomy and self-determination.
But you do realize that you're going to be treated that way regardless of whether it's overtly or not, right? That's why you're paid by the hour, not by how much your effort contributes to the bottom line (supposing for a moment that that could be accurately quantified). When you become an employee you do agree to become a cog in a machine. You're not some independent artist making your own way in the world, you're working on someone else's project and following someone else's success criteria, along with a bunch of other people. An employee gives up a small amount of autonomy and self-determination in exchange for stability. If that's not what you want perhaps you should become an entrepreneur.
I honestly don't understand how being asked to perform a wildly different task is much worse that the default state of affairs. If it were me I'd think "hell yeah! You're paying me the same money to go fetch coffee? The hell do I care?"
>I'm implicitly agreeing to literally any of those policies by agreeing to employment to any single one?
No. But it does make those policies not unreasonable. It can't be unreasonable when so many other places have said policies. That the place you're at isn't currently one of them doesn't mean it can't be one in the future, nor does it mean that it changing would be unreasonable. You especially can't put on the surprised Pikachu face when so many companies are doing it. "Wha... What do you mean in this software company they're requiring people to return to the office like they're doing at all the other software companies? This is totally unexpected!"
>In some societies (but not the United States), a company unilaterally trying to change the terms of employment in a way that the employee disagrees with is grounds for the employee to receive severance.
I live in one such country, and most people would still rather negotiate than just be fired with severance, or even just bear with it and start looking for a new job. All severance does is make it so small and medium-sized companies can't fire a lot of people at once. It's still a bigger blow to the employee, even with severance.
>I fundamentally disagree with the presumption that I need to be willing to present a company with an amount of money for them to force me to change my circumstances; if they're the ones who want to change things, the onus should be on them to convince me, or else they should be required to compensate me for their unwillingness to continue with the previous agreement. This isn't how things work with "at-will" employment though, and the number of software companies in the United States that offer anything other than at-will employment beyond finite length contracts are at most a rounding error above zero. This doesn't mean I have to think this is fair or reasonable; quite a lot of things in life are unfair or unreasonable without being within our individual abilities to influence, and it's not hypocritical to be willing to point those out even if I'm not willing to risk the livelihood of myself or my family to make a point about it that will in all likelihood change nothing.
To be honest, I'm not sure what your point is anymore. All I said was that if circumstances change and you and the other party can't come to an agreement, all that's left is to dissolve the business relationship. Everything else around that simple fact, such as the particular terms of the business relationship, seem to me largely inconsequential.