Human labour is by far the most expensive aspect of taxis. If a tax driver earns 35,000 USD/yr, a self-driving car only needs to cost < 35,000/yr to turn a profit at scale.

IIUC, FSD costs are mostly captured by the running service, and the lidar equipment. The lidar equpiment is < 20,000/car for sure, and I can't imagine it costing 15,000/car to service it using waymo's ride hailing platform at scale.