The article points out very nicely that it is expensive (in space terms) to have cars integrate safely with the pedestrian and bicycle traffic of dense urban areas. The mismatch in size and speed requires buffer zones that must be dedicated to this function only.

Roughly the same size as if the street had 2 car lanes on each side. In fact this is what I've seen living here in Amsterdam for a few years, every once in a while they remove a lane or two from some street and beef up these security features as well as add more pedestrian space.

It's cheaper to maintain extra fat sidewalks and stuff than 2 more lanes of asfalct also.

As a Dutch citizen, I love the expanse in terms of space. Lately, they have been allocating a lot more green areas as well, making the whole experience very enjoyable.

Example: https://zuidas.nl/wp-content/uploads/2021/03/groenstrook-bee...

On the other hand, the reduction in cars due to people switching to cycling makes the infrastructure incredibly cheap.

Look at the video in [0]: how much space would you need if every single cyclist was driving a large SUV? Look how smooth the traffic flows through the intersection, how many flyovers would you need to achieve this with cars?

Yes, cycle infrastructure does indeed take up a nonzero amount of space. But it easily pays for itself by reducing the need for far more space-consuming car infrastructure.

[0]: https://www.youtube.com/watch?v=2RQrKP9a0XE

A bidirectional bike lane takes about as much space as one lane of on-street car parking, which american cities have plenty of. Swap half the parking to bike lanes and that gets you most of the way there.