I suspect you’re getting downvoted for the pneumatic tube sentence, because tube systems like that have proven to be way too inflexible for a rapidly changing city. And expensive. And hard to maintain.
I haven't really seen any research on packet-switched pneumatic tube networks, or any kind of more complicated routing. Every time I've seen one in person it has been more or less point to point, or point to mailroom. I think modern sensing tools, either NFC or high-speed cameras, have the potential to enable some significantly better topologies than what I've seen in real world pneumatic networks.
Also looking at projects like the hyperloop, I'm wondering if a smaller version linking cities would make sense. We already have infrastructure for transporting oil and natural gas through very long pipelines. How about actual packages? If the hyperloop can make sense, I feel like inter-city mini vacuum train probably can as well, and linking two cities together doesn't require any great flexibility.
I've a friend who thinks drones are ultimately a better solution than tubes, which is also quite plausible. I don't really care much how it gets done, I want <10 minute automated delivery directly into my residence (hot food stays hot, cold drinks stay cold), and I imagine millions of others do too, if for no other reason than to make homes entirely without kitchens or refrigeration feasible.
But I agree with the rest of your comment.