It sounds like Prim did exactly what it was supposed to do: test the market. If there was indeed a strong enough market, they could work on creating a more efficient business without the need for outside capital. Investors are not in the business of throwing money away so people can get their laundry done, yet that seems to be exactly what the author is trying to say.
"Perhaps that money could be better spent helping people in need, and maybe so could the founders’ time."
Startups are incredibly capital efficient at testing needs. Even if there is nothing there, a lot of experience and knowledge is attained. Could such capital have been better allocated elsewhere? Probably not when you look at the potential upside.
It's surprisingly difficult to build an efficient delivery service. To succeed you need knowledge of the peculiarities of the delivered goods, effective management of the delivery staff, and of course clever software. Route optimization and dispatch are interesting problems, but quality tools for drivers and other staff are just as important!
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