AB5 is the stricter limit CA is setting, no? The legislature does have plenary power to "enforce a complete system of workers’ compensation" but no one's going to undertake the challenge of massive labor reform challenging Borello and the ABC test for Ubers' sake, especially when it's so contentious (for what it's worth, I'm slightly biased because of the fear it'll open the door to other labor law poison pills). AB5 brings the existing framework into spec with Borello/Dynamex and clarifies open questions.

That's why Uber, Lyft, et al have thrown almost $200 million behind the prop 22 marketing campaign. Even if the legislature overturns AB5, the core reasons behind the court's decision remain for future lawsuits to hammer home. AFAICT Uber's only hope is the CA Supreme Court not doing to Prop 22 what it did to Prop 8 or Federal reform. They're not going to get it from the state legislature.