Lyft doesn't provide car seats or booster seats anywhere. Never did. Über has stopped bringing on new contractors with car seats (also never offered boosters). At some point, all their carseat drivers will have left. https://**************.net/2019/06/lyft-official-rideshare-service-disney-parks-ba "So what does this official partnership mean for Disney vacationers? Well, Disney shared that new enhancements will be added to the Walt Disney World Resort Minnie Van service this fall 2019, as Disney and Lyft collaborate on exciting ways to continue to make Minnie Vans even more magical for guests during their vacations. This fall, it will become easier than ever before to request a Minnie Van ride, find the most convenient pickup location, and even request a wheelchair-accessible vehicle, all while using the Lyft app on your Walt Disney World vacation."
It sounds like Lift is the official rideshare specifically because of the reservation platform for requesting MinnieVans.