Software might be a differentiator for a while, but it'll likely get commoditised. Self-driving doesn't involve complex UI with high switching costs and has little network effects / virality. And Google doesn't really have distribution locked down for self-driving cars like Search or Gmail.

The hardware on the other hand might not get commoditised so easily. It might have patent protection. If nothing else, high capital costs will mean monopoly or duopoly with enough profits.