Loads of European cities and towns have developed extensive pedestrian-only zones. It doesn't necessarily bring life back after the Covid years. Many people today are going out less regardless of what nice amenities urban planners provide, and having food delivered appeals more to many young people than actually visiting an eatery.
I'd say it's necessary but not sufficient. The place has to be a place people want to be, and cars are just one part of that.
My observation in europe is that pedestrian only areas in city center tend to be the most commercially successful areas in large cities.
In small towns maybe less because most people going shopping aren't from the town itsef but its surroundings so if they need to bring a car in the first place, they'd rather go where they can park it. And this is somehow a failure on how most european cities have tackled mobility itself. A lot of urban areas have been equipped with more or less secure bike paths, but they too often become impractical or plain dangerous outside in the larger area outside of the cities.