I work in big tech, and you would be amazed at how many people will openly decry pure acts of malice against employees - laying off the day before their stocks vest, removing remote working, gaslighting, etc, but who will also openly decry forming a union.
Funny enough, even highly educated people have some weird notions about what a union would do for them. They think it'll make the workforce weaker, will reduce their salary significantly, and will promote laziness and job losses throughout their teams, with absolutely zero evidence to back it up.
What these people are doing is literally paying for the benefits of a union, without the actual union aspect, and with very little power on their side. All a union needs to be is:
Collective bargaining for a minimum salary offered
Access to a union rep for disputes
Access to a union lawyer that specialises in conflict resolution
That's it, and all for a small fee every month/year.