It's bad because our historical growth is based on us accumulating things using credit. Producing and consuming things is what creates job growth which sustains our growing population. Our acceptance of inflation due to said consumerism, credit, and the black hole of the federal reserve issuing new currency is what provides "new money" for investment in research. If we transition to a society where things are no longer valued for possession I have to think that we won't care to share them either. If a car is not cool enough for me to want to own, why would I care to use the communal car rather than the bus? Can the auto industry survive selling 10% of the vehicles is does now? Will consumers pay 10x what they pay now, it costs no less for R & D, all while not truly owning the thing? This communal ownership changes half the paradigm, the funds to rent the items still needs to come from an economy that relies on people buying things to own and those things becoming unavailable to the rest of us forcing new consumers to buy new things from a factory and hopefully destroying it or hoarding it before it hits the secondary market. I think we need to stay on the current path until we have abundant free energy.

Add: I also feel this is why new home sales is such an important metric to judge the momentum of the US economy, lots of new home sales means lots of new home-wares. You buy or build a house you also buy a refrigerator, microwave, carpet, furniture etc. Mostly on credit. If we truly become a communal society the cycle is broken, the same people who said "no new house and no new car, I'll just save my cash" now earn less 5 years later because there are many fewer things sold and the interconnected supply chain stalls.