I think this is one of the key quotes:

“It used to make sense to require parking in homes to avoid public spaces being filled. But this generates traffic because it encourages people to drive. Young people are also less likely to own a car. They may either opt for car sharing or renting.”

There's practically no free public parking in Barcelona. It's either for-pay or you have a resident permit.

I hope this frees up space, not just for sustainable transportation but also for more affordable housing, something Barcelona really needs ...