US Federal highways were built for homeland defense first, then commercial traffic, then individual automobiles. The infrastructure is built on government credit and maintained via gasoline taxes. A 50 mile segment of freeway might move more than $50 million worth of cargo and labor each hour. The same is true for city streets, on a smaller scale.
Bikes, by their nature, are rather terrible at moving things around like cows, refrigerated goods, building supplies and such. They are excellent at moving around people, and providing them healthy exercise in the process.
The demonstrable economic impact of a road closure in terms of real wages, purchases, freight, and more is analyzed with incredible depth here:
https://www.purdue.edu/discoverypark/nextrans/assets/pdfs/Fi...
From an economic standpoint, the value that bike transportation facilitates is the aggregate value of the wages, production, and consumption of its riders. They represent 0.6% of urban commuters, with 86% in automobiles and 5% in mass transit. Even in Portland, OR only 3.5% of the workforce commutes via bicycle, and certainly less on the rare snow day.
Many would argue that our transportation infrastructure is the cause of this disparity. I think that they are in fact a reflection of economic reality. In places where bicycles carry lots of economic value, such as a highly compensated workforce, they have more infrastructure. In places where they convey relatively little economic value, they receive virtually no accommodation. In agricultural areas, roads have special accommodations for tractors, and rail is extremely valuable.
I could imagine, as many have and the article suggests, a vision for urbanism that is centered around human-first transportation networks. In a place where knowledge work dominates, this is entirely possible. Its happening now, in NYC where roads are being closed off to cars block by block. The roads themselves still exist because people still need things that are most efficiently moved by trucks, such as refrigerated goods, construction equipment, and so on.
A pedal-powered utopia would need to have a robust solution for moving kilotons of things like food if people want to eat, building materials if people want shelter, stuff if people want stuff to put in their shelters, and raw materials if people want to make things instead of just consuming stuff.
Bicycling provides plenty of recreational value, which is in itself economic value, and that should not be discounted.
If we're envisioning things, I'd like to see integrated networks of airborne, ground-level, and subterranean conveyance, each with macro, micro, and intermodal transit solutions that have maximal economic bandwidth and minimal environmental impact. Better yet, technology that eliminates the need for transit, like localized manufacturing and recycling... ie, instead of a garage sheltering a car, it could hold waste materials, shredders, extruders, 3d printers/fabbers, etc for anything from plastics to proteins. If everything we needed to transport could be transported via bike or drone at the last mile(s), if everything we needed came in small packages, if labor happened in place, if everything we made came from commodity components and openly shared designs... roads would vanish rather quickly.
Until then, bikes will get the infrastructure budget commensurate with the value they transport, and the same goes for each other mode. At least cyclists don't have to pay gas tax.