Technology

Yes, because there’s no union there to bargain for better pay, bonuses, more time off work, and so forth. Tech is a new industry where workers have more bargaining power on an individual level because expertise is so sought after.

We're in agreement. The individual has all the power to bargain for themselves better pay, bonuses, more time off work, and so forth. A union in this case not only adds no value, but subtracts value because it dilutes the benefits across more people. There is certainly a good chunk of dead weight in IT, those that let their skills stagnate or don't put in effort to the team. I've worked with a number of them. At one point I've personally been one of them before I understood it. Much of the individual bargaining means gaining resources that, if spread evenly, would go to some of that dead weight. Keep in mind, even dead weight in IT pays pretty decently. Those folks aren't going hungry. In some ways its one of the few partial meritocracies left, though merit here is not only technical skills but soft people skills combined.

We’d likely also have more time for tech debt, as unions increase certain types of innovation.

Again, this is mostly an organizational benefit, not an employee one. If the employer doesn't heed the warnings of the employees that tech debt is increasing and becoming a business risk to the organization, the employee doesn't have to fall on their sword to try to save the employer in spite of themselves. The employee jumps to another employer which pays more (or requires less hours). The new employer may have equally or possibly even more tech debt. So the situation for the work is unchanged but the employee's salary and benefits are increased. This is the mercenary culture of IT I was referring to.

Why would we assume tech workers in a very profitable industry wouldn’t be able to get away with even more?

Because those at the far end of skilled are getting less to level out those that are less skilled or less committed. Ultimately it IS a zero sum game.

Keep in mind, many IT skills can be very "flash in the pan" or trendy. One year you're in extremely high demand able to demand top dollar, and others your skills are out of market favor and saturated with IT workers with the same skills that aren't in demand and what you can earn with what you know is drastically reduced. It requires the constant prognostication of what going to be in demand next, and the effort to learn those skills to be skilled up if those skills go up in value for a time. Its a huge gamble. You bet right sometimes can demand a kings ransom for more hours than you can bill. Other years you bet on the wrong skills and have learned something nearly worthless or so short lived it wasn't worth the effort.

Savvy IT people (and other industries that work the same) understand this cyclical nature and save during the fat years to be able to live okay during the lean years.