Sharing my startup co called Capava. It's a private credit platform connecting U.S. investors with short term debt opportunities for vetted African small and medium enterprises. Earn 12 - 20% annualized yields on your investment, paid back to you monthly. All opportunities are with businesses that are growing and every deal goes through a rigorous due diligence process and fully collateralized.
I see your point but there is still usable space going up in many places. In NYC for example, many buildings have garages with open air space that could be used to provide more parking. The cost of the space doesn't change whether you are parking 1 car there or stacking up. Might as well utilize the space to give more cars access to parking as opposed to just using for a single vehicle.