Prop 22 bypasses a state law that would have reshaped the gig economy.
The ballot initiative in California would allow companies like Uber and Lyft to keep classifying workers as contractors.
The dispute could put jobs at stake during the pandemic.
The labor movement of the future moves beyond traditional collective bargaining, says former SEIU Local 26 President Javier Morillo.
The ride-hailing companies now have 10 days to appeal the ruling.
If the $600-a-week pandemic payment disappears, many may have trouble covering their basic expenses.
Gig platforms have long been ambivalent about encouraging tips that many workers depend on.
"What are we supposed to do when we've got to stay apart?" said musician and writer Dessa.