i think cian makes a very valid point with a solution.
without historical districts with review committees to oversee the modifications and protect old valuable buildings, the developers will come in and build with only the money in mind.
this developer mentality makes every design descision based on building code minimums and maximums. old buldings are expensive to maintain and renovate. building new with similiar features as the older buildings is very costly.
unfortunately even our contemporaries lack a level of quality in thier work. it would be nice if all architects were ethical and had good taste, but they are often only puppets on the developer’s payroll.
government regulations and urban planning are the only way to regulate the shape, flavor, and style of city.