American here: Do places like this exist en mass in European countries and this is something that's coming fresh to America? Most American restaurants seem to try and hustle you out, not invite you to stay for another meal.
The cafes are where people relax and people watch. No need to rush.
While cost kept me from doing it on a daily basis, I quite regularly ended up spending entire days (8+) hours at the hotspot-du-jour, only leaving for brief periods for some errands nearby.