The more drivers a co-op has means shorter wait times and higher geographic coverage for the passengers. If passengers have to wait too long, they will lose faith in the reliability of the co-op and be forced to use other forms of transit.
The more passengers a co-op has means drivers have to idle less or shorter (unpaid) distances to travel to pickup a passenger.
It is always better for the co-op to have more active drivers and more active passengers. The growth comes in the form of "let basically anyone join".
None of the co-ops listed have industry standard safety systems for telematics (unplanned stops, detour detection, or unsafe driving), face recognition, or audio recording.
Feel free to address the original point of how co-ops have the same incentives as Big Tech for letting anyone on the platform.
And what you said is true, but it's also a vapid statement without looking at percentages and incentives. Individual bad examples exist everywhere, but a workers coop of drivers in a City has social incentives (if a driver from your coop robs someone who goes to the same church as you, you'll hear from it) and constraints (if your cooperative gets boycotted in your town, what will you do, move everyone next postcode?) which uber lacks (if there's a boycott in one town, bad for the drivers, but you just put out a press blurb, do a promotion and donate to a charity and wait until things die down)