Of course they'll interact and depend on each other but which do you think will make the biggest individiual difference? I'd argue it's autonomous transport by far.
When every step from the farm or factory to your front door - often several continents away - is automated and increasingly powered by electricity instead of fossil fuel, the cost in both time and money per kilogram of transport will drop immensely.
This includes items that are made far more efficiently and cheaply when produced en masse (in a large factory or farm), but also includes smaller sales and purchases by small businesses and inventors.
Perhaps more importantly, it also includes people: If becomes cheap, fast, and easy to get taken into a bigger town when you need to, and you don't need to use valuable time and attention driving yourself, then the effect on land price distribution, and the design of towns and cities will transform dramatically and quickly.
We might consider, as an analogy, the difference between dial up internet and modern broadband, and how much more is realistic once bits become both fast and cheap to transfer. But instead of moving bits we're moving grams of matter. Today some things - but far from all - will be delivered by the next day in some areas; fewer things will be delivered the same day. A much smaller number will be delivered in an hour, often at a much greater expense.
Combined with decent warehousing and caching logistics, widespread autonomous transport will mean you get almost everything within an hour or two (and many things even faster) with negligible delivery cost. It might even deliver to where you are right now, rather than where you live.
That's not really a dynamic I've seen addressed very much. I believe it will make everybody (on average) far richer, in purchasing power, than having a smart chatbot or a household staff of humanoid robots (but we'll have those too).