I have a theory that this service is to allure
drivers more than
consumers. Given that consumers had an option of using Lyft Line or Uber Pool for their daily commute anyways, Lyft Carpool don't add that much value other than perhaps cheaper fare. On the other hand, for the single drivers, this sounds like a good opportunity to make a side income without a huge impact on their lifestyle. Probably another 10 minutes of their lives picking up and dropping off a passenger, and they get paid a few hundred extra bucks a month.
I have never thought about being a Lyft/Uber driver, but I am seriously considering registering for Lyft Carpool, and who knows? If I like it, I might become a Lyft driver as a side gig.