The megacorps created a situation in which thousands of people are jobless and with stagnating wages, while they hit record profits.

What is stopping Fastmail to employ the playbook of the megacorps and do a couple of rounds of layoffs? Or to simply stagnate the wages of their employees, citing "bad economic headwinds"? Or to fire some high earners and replace them with cheaper ones from the huge pool of the qualified jobless? That's right, nothing stops Fastmail, unless its employees are protected either by law, regulation, or belonging to a union.

In Australia labor protections, while not as woefully inadequate as in the US, are still not enough to give workers a good guarantee of safety and bargaining power. Hence, they formed a union. It's as simple as that.

While unionizing to fight mega corps is one stratagem, the industry benefits as a whole when unionizing is the standard regardless of company size.