While I currently do not own a cargo bike, I would love to get my hands on one and use it to haul groceries, supplies, and the cats (I think they would enjoy it). I think people underestimate how effective they can be at hauling goods. Xtracycle has a cargo bike converter kit allows your bike to be capable of hauling over 200 lbs. I’ve also seen some impressive posts about people moving entirely by bike.
This video talks about a cargo bike revolution coming to the states. I’m not convinced this will happen in my city considering how difficult it is to get some lines painted on the streets, let alone safe paths to haul kids in cargo bikes. Locally, I do not know of any shop that has a selection of cargo bikes. Usually just a trike with a large rack on the back.
For cargo bikes to be accepted I think you must have safe routes to local shopping centers, schools. and grocery stores. Unfortunately, many places hardly provide sidewalks, let alone bike paths.