I recently returned after touring a number of European cities, virtually all of which, big and small, had pedestrian and vehicle-restricted business streets, all of which were vibrant and exciting places to be: Zurich, Prague, Copenhagen, Stockholm, Gothenburg. In Oslo we were delighted to find that the five blocks between our hotel and Central Station could be walked on pedestrian streets. Zermatt, famously, prohibits private vehicles on all its streets. (Though better keep your head up: shuttles and service vehicles are everywhere.)
If there is a flaw in the Argyle Street redevelopment, in my opinion, is that it encompasses only half of the street: the remaining two blocks should have been completed at the same time. All of that said, we have a great resistance to change in this corner of the continent and acceptance will not come overnight for many people. A buddy heading to Neptune on the weekend was bemoaning the loss of parking, even though the overall number of spaces closed on the two blocks is minimal. Saturday's street party was a good start but it will take much more effort to bring people to the street and keep them there.
Copenhagen's Strøget is said to be one of the world's longest car-free streets: