Waymo never had any intention of manufacturing their own vehicles. They've been failing at finding a secure manufacturing partner for about 4 or 5 years now. Sebastien Thrun and Sergey Brin went into a number of auto executive board rooms basically suggesting that the auto industry should be ecstatic to become like foxconn, a brandless low-margin manufacturer of hardware to support Google products and services. The response from auto execs was basically "Fuck that noise", and the carmakers are responding aggressively to the shots that have been fired across their bow.
Longer term this is a problem for Waymo. Their supposed partnership with Fiat Chrysler isn't a full-blown, intergrated manufacturing partnership. Waymo is mostly just buying Pacifica mini-vans from FCA and retrofitting them with Waymo's own custom designed hardware at a separate facility in Nova Michigan.
This is not cost effective, and not viable as a long-term strategy. If Waymo does have a strategy for producing robotaxis in the tens of thousands, they've been very quiet about it.
With every year that goes by building an autonomous OS gets easier. Best practices have been established, knowledge continually disseminates throughout the industry, there is, every year less software and hardware that needs to be built from scratch. Automobile mass production, on the other hand, isn't getting any easier. It's as hard as it ever was. So really, over the long run, it's the legacy automakers who have the true competitive moat, and the real bargaining power.