Wrong emphasis. Society depends on people*, doing their jobs.

Let's taboo some words:

• Society: a sufficiently large group of individuals. Are we assuming a shared final goals? A power structure? A distribution of labour?
• depends on: requires for its continued... What? Existence? Prosperity? What aspect of society depends on "people doing their jobs"? What does society depend on "people doing their jobs" for? For now, I'll assume you're using "depends on X" in the sense of "expects X to happen"... but that's kind of weak.
• people: individual sentient beings, not machines or tools, with needs other than being kept in optimal condition for the performance in the functions they perform, and existences that do not necessarily revolve around performing said functions.
• doing their jobs: performing the functions that they have promised to perform reliably and within certain sufficient quality and quantity parameters

Again, given that it's people we are talking about, they will only want to do their jobs in exchange for a reliable retribution in advantages in the shape of wealth and status in sufficient quality and quantity that have a utility to the people that is equivalent or superior to costs that "doing their job" entails for them. They will only be able to do their jobs if the compensation is sufficient to keep them alive so they can come back the next day.

Now, let's use some basic economic theory: let's assume work is a commodity, that is, let us do away with the "people" part and suppose the job-performers are emotionless, non-sentient machines, tools that will simply go irreversibly out of order if they are given insufficient resources for a long enough period of time, beings that exist only and purely to do their jobs, whose downtime is either spent in maintenance (and can be shortened or lengthened depending on where the optimal total productivity point between maximum duration and maximum instant output lies). Let's also assume that their work capacity is distributed in an ideal free market, and that the machines are programmed to ask for as many resources as you are willing to give them. There's a very close real-life equivalent to said machines: cattle.

Finally, let us assume that there is a steady influx of new machines, but that the work that the society needs to get done fluctuates.

This situation automatically results, thanks the to wonderful "Invisible Hand" that guides the self-regulating ideal market, into the jobholders being given *exactly as many resources as they need to work and keep functioning the next day, maintaining exactly the population that can provide the necessary amount of labour needed for getting the amount of job that society demands done.

Now, in the XIXth century, that is often what actually happened, except with people, specifically unqualified labour (heck, look at the very term: "unqualified labour", as if labour was everything they are). And that was just unplanned market fuckery. The Nazis would actually planify killings by giving workers rations that were exactly calculated so that they would die soon upon completion of the project they were assigned to.

Why did this happen? Because those workers were powerless to make the people who had the right to set the conditions of the job agreement give them anything more than what ensured what was strictly needed for them to perform their task, which was basically them being alive for as long as they were needed and useful, and not an instant more. Which was what they ended up actually getting, because a free market ensures that's where the Nash Equlibrium lies: they are locked in a prisoner's dilemma in which if any single one of them refused to agree to work under those conditions, they would simply be replaced by another, willing person, and then die.

This is why as long as we assume that job-performers are people, more than tools to be used and thrown away, that their existence has value beyond the utility derived from them performing their jobs, and that it should not be entirely miserable, it is absolutely vital that job-performers have a form of power over those who set the conditions of the work agreement, that will allow them to protect themselves from being reduced, by the sheer strategic necessity, to the status of tools.

Now, strikes are a horrible way of achieving this: they are self-regulating too, in that, performing them is at the immediate cost of the job-performers (of course, since they are paid less than what their job-performing is actually worth, this costs whoever profits from their job even more) and risks the cessation of the demand for the job itself being performed. So, game-theory wise, it works, ideally resulting in the job-performers being assigned just under the amount of resources that would make the net utility of the job being performed inferior to that of it not being performed.

If you have suggestions for alternate ways in which job-performers can protect themselves from becoming cattle or machinery, I would love to hear them. I say this in all sinceirty: strikes are ugly. If you can additionally justify why people should not have the right to strikes, given those alternatives existing, I would love to hear that too

Then you will abstain from going swimming: if you don't, it will be at your own risk and peril. Though bad working conditions in this case is more likely to cause people to quit, and a scarcity of appliants (which means you'll have to take unqualified people or close the swimming area for longer periods of time): it certainly won't be a manner of being overexploited by abusive leadership. Overexploiting a lifeguard by assigning to them a larger area than they can effectively cover simply means they will fail at their jobs and people will die, so that's not an option either.

The exception puts the rule to the test, and, as I have shown, lifeguards are an exception in more ways than one.

But, as a general rule, and given the way power dynamics function in the modern workplace, I would argue that the right to strike is an absolutely vital part of the checks and balances of a healthy economy.

Not to say unions can't act petty or spoiled at some points, but that attitude is self-defeating, and the existing counterpowers will stop them soon enough. That's what checks and balances are for: selfishness keeping itself in check.