A parking garage would be built catering to vanlife visitors. It would have amenities for them and both short and long term parking pricing. The price would probably have to be kept a good bit lower than campgrounds, as their natural settings and added space offer added value.
Each parking spot would be a bit wider than a normal parking spot to give room to have a small setup outside of the vehicle, tables and seats or whatever. There would be some tables and chairs or picnic tables in a shared area on each floor as well.
Each spot would have a 120 volt AC electric outlet similar to the electric campground spots. Some spots might have 240 volt for electric vehicle charging. There might also be a water spigot and drain, but more likely there would be several spigots and drains spread across each floor. There would be a shared restroom area with showers and a dish sink on each floor as well.
There would probably be vending machines on each floor. There could also be a convenience store, laundromat, possibly even a restaurant, car wash, gas station, mechanic, and other amenities on the first floor and / or other floors. These would be somewhat focused toward vanlife needs. The store would likely have a lot of vanlife and camping equipment, for instance. There would also likely be various related books available, and perhaps an on-site expert to give advice and answer questions.
There might be a grassy or treed area adjacent to the garage with a dog park area, walking path, and benches to sit for convenience and to make up for missing features from campsites.
For long term tenants, there may be a mailing service provided where they are given a mailing address for their spot and can pick up their mail from a shared area like an apartment building would have.
For tenants who want a break from the vehicle, there may be an in-garage motel of sorts, a room with a parking spot right by it. The motel rooms might all be to one side on multiple floors to leave space for ramps, etc.