Earlier quoted context omitted.
Here is where the primary AB5 bill sponsors get their money: https://www.followthemoney.org/entity-details?eid=37194&defa... https://www.followthemoney.org/entity-details?eid=133178&def... List of all sponsors: https://legiscan.com/CA/sponsors/AB5/2019 As you can see "Labor" is by far the biggest sponsor to the politicans who pushed through this initiative.
I don’t understand, why is that surprising? After all the reason behind this bill is to prevent unfair labor conditions. It is literally the job of labor unions to push forward and lobby for bills like these. I think you are guilty of bad faith reasoning here. First you state that “big labor unions want more power” and your evidence for that claim is “Labor unions push for bills that prevent bad labor practices” .
To help point you in the right direction, why are the United Auto Workers acting in California when there are no unionized auto workers in California? These unions are always seeking to increase there member base because the more members they have the more powerful they are as an entity.