Just because you're working together in a circumstance that benefits the two parties doesn't mean each party is not also working against each other to some degree to better optimize their self-interests.
An employer may need an employee to create something and by creating and selling that thing, an employer and employee may both get a cut and benefit. None of that prevents the employer or employee from attempting to get a larger cut or do less work (invest less time) to receive their cut. Extremes to either side cause the relationship to collapse but there's definitely wiggle room in the margins beyond a 50/50 split.
I've yet to meet a single employer that doesn't try to optimize on labor costs in that relationship through some component or another, directly or indirectly.
Which is also true. At the same time, risk is highly relative which is why this situation is feasible at all. What's risky for you to do as an individual is not of the same order of magnitude of relative risk when you consider scaling of available resources.
Example, Alphabet, Amazon, or Company Y decide to invest $1 million in a new SaaS 'X' effort with some monthly fee in an attempt to build a successful product/service. These companies have arrays of pre-existing successful products/services they've built (typically diversified) that generate stable profits. Relative to that sort of expected profit, SaaS 'X' is a drop in the bucket. If 'X' fails, it's the same absolute monetary loss ($1 million) but the relative risk of losing $1 million isn't significant to any of these businesses, it's small relative to their total resource pool of disposable assets. Loss recovery will also take significantly less time.
On the other hand, if I as an individual go through the effort to form an LLC, develop SaaS 'X' myself and fail, $1 million is nothing to scoff at. Even if you're in the higher income scales of our industry and making $300-500k+/yr for labor, you're looking at ~3-4 years or so of potential losses and values that are probably near or a bit more than your total personal assets, at the very least I'd say 10%. If you start an LLC and get a loan or have some investor drop money on you, $1 million is still likely going to be a lot relative to your loan. It's highly likely that if 'X' fails your business will fail. There's high relative risk here (there are some mitigations strategies from your personal assets but it's still significant). You're probably going to face noticeable financial hardship or have to revert back to the labor market due to business small failure rates.
Risk is mitigated through scale, snowballed growth, and diversification (amongst other strategies) in our economic system through initial successes that often occur either through true innovation/market creation/penetration and/or sheer luck.
My personal take on things is that if you don’t recognize the adversarial part of the employer/employee relationship, then you will suffer for it. It’s more healthy to recognize where parties have competing interests, and it’s unhealthy to ignore them.
I’d also say that the people who can ignore the adversarial aspects of employment can only do so because of a fair bit of privilege. For example, people will throw around the saying here that “HR is an advocate for the company, not the employee,” but many of us will never really have to deal with HR in a way where it really matters.
I'm not sure I'd agree. When a company loses an employee it's an inconvenience but when an employee loses their job it's often devastating.
The market rewards them for this. Is the market wrong, or your thesis?
Your employer needs employees, not specific employees.