Wouldn't they be even better suited to a regular electric car, parked under a roof of solar panels? The simple flat solar roof will be cheaper to make, and be a larger useful surface. And easier to replace, will keep the weather off the car, reduces car weight, etc.
It seems non trivial to me.
You seem sceptical? I've seen exactly that in a street near me, to a motor vehicle being charged up. They used a cable protector, this kind of device: https://www.kingfisherdirect.co.uk/traffic-line-hose-and-cab...
However, more permanent infrastructure would be buried below the paving. This already happens, BTW. Cities need infrastructure, that's just the fact of it. 21st century infrastructure will include fast internet and vehicle charging.
I'm not arguing against the idea that such infrastructure would be good. I'm just saying that a private person renting an apartment in a city can not reasonably be expected to slap solar panels on the roof of the building they don't own, illegally run cables over the pavement they don't own to their cars that may or may not be possible to park near the building they live in.
To them, a car that "charges itself", even significantly less efficiently, may indeed be a better solution.
Since I was out and about today, I took these pictures
The first picture shows the cable with protector, that a neighbour uses. It's not in use but you get the idea.
The second shows more permanent infrastructure - a charging port built into a lamp post. Picture taken across the road from the first. Note the logo of https://www.ubitricity.com/ and instruction sign. Sometimes I see new model LEVC taxis plugged in there.
The cable guide there is there so that prams etc can get over it without much trouble, and so that pedestrians don't trip.
The unknowns at this point are: what are people willing to pay and how much additional weight will they tolerate? And, how light and cheap can these panels be made with the technology available now? And whatever these numbers are now, they may change as public opinion, the price of energy, and technology change. It may be too early for this to be a viable product, or maybe not. It's good to see someone is trying it at least.
Also: a solar carport might be technically easier to make, but it will require building permits and probably hiring an electrician and manual labor assembling the structure and so on. And some people don't own the land they park their car on, and many people drive to work and park their car in a lot that either doesn't have solar roofs over the cars or the ones that do use that power to cut down on the company's power bills.
"worth" here implies the third factor that you didn't explicitly mention: how much power you get off them. And "69 miles per week of charging" is pretty small, hardly worth it unless it's extremely cheap in vehicle cost and weight.
You're not wrong with the qualifiers "people using their cars once or twice a week to drive 10km to do groceries" and "some people don't own the land they park their car on" but each qualifier of the prospective customer greatly decreases the potential market size. Combined with a qualifier that they must be without good access to shared transport (so not in a big city, but not on their own land); then you might be looking at corner cases, not a viable market.
While the technology isn't there yet, it seems likely that this will eventually be the case.