Big problem in the US; high taxes for bloated bureaucracy chase many people and businesses away from established downtown areas (even in suburbs, in the case of NJ). People are coming to understand that the price of maintaining our government worker class is killing them, and those built-in costs are rising constantly (often related to people who retired years ago).
The politicization of race issues hasn’t helped; an increasing number of people see no reason to expose themselves to the unassimilated predators that frequent such places.
More than costs for bureaucracy, is the availability of transportation. Prior to ~1910 most of the US had a small market every 3-10 miles with ~6 miles being quite common. The smallest dried up and blew away before 1930. With those large enough to have broader services lasting into the 1970s. It is the availability of personal travel that killed the small towns.