We are family of 4 with 2 small kids. Whenever we travel, its a series of backpacks, other bags, other stuff, and then some more. Heck, even if I travel alone its almost never just me - there are heaps of garbage to dispose, big shopping bags to bring back, big backpack with camping or climbing or skiing gear etc.
It would have been absolute, utter nightmare to do this over public transport. This comes from European who has generally very good public transport (given rural area) and world's best train network specifically (Switzerland). Yet roads are choke full of cars and every year there is more.
Public transport simply ain't cutting it for anything but the simplest use cases, ie just me and nothing or small backpack. Some routes I take would take 3-5x longer with public transport, or are just not possible at all. No industry massage required here, ever. Not everybody lives in some dense city and never leaves outside for evenings or weekends.