They perhaps were for some time, but both Uber and Lyft sold off their autonomous vehicle divisions a few years back. It makes more sense for an established car manufacturer to develop this as they already have the infrastructure to scale this and not require Uber to work on just software/hardware and rely on licensing or contractual agreements with car makers.

They’ve probably both realized it’s a very difficult task to go beyond simple routes and that it’s not a viable investment for a non-profitable company that’s burning through investor money trying to establish a monopoly.