Also, in my opinion, they pretty much have to go all-in investing in self driving cars because any market waymo launches in can easily outprice uber/lyft especially considering that while uber has a lot of cash, google literally has an order of magnitude more on hand + they still rake in gobs full of profits from search.
And for the eventual "waymo cannot handle rain or snow and probably won't be able to handle it for years" argument: almost all of the taxi driving market is under normal conditions. It will almost certainly be profitable to just service customers when weather conditions are fine and then park their cars in bad weather.