The law certainly makes a distinction, and bigger-pocketed defendants, in practice, are forced to pay more per wrongful death than 17-year-old Johnny with just an auto liability policy.
Not saying it's right, but that's how the law currently works.
Even if the liability does fall on the big players (imo it probably will) and autonomous cars are no safer than a 17 year old, at 10x that is only a few thousand a month in insurable liability - or much less than the cost of paying a cab driver a living wage + benefits.
Never mind that autonomous driving, once technically 'solved', is going to be a socioeconomic freight train that will have the resources to lobby and favorably influence legislation and judicial judgements.
Not saying it's right, but that's how the law currently works.