what is really needed is very fast public transportation from outside cities to the cities themselves, and incentives for workplaces to split into sub-branches in other nearby locations instead of endlessly expanding within the same city.
most people would prefer living outside the city for cheaper and higher quality of housing, the force pulling them back towards the city is the transportation distance to work. the force pulling workplaces into the cities is that they want to minimize transportation time for potential employees (unless the workplace has a location tied to the city), while they still need to cluster employees who have to work together.
so everything is clustered, and there's nothing to do about it.
only way that this can end, is if you reduce the force pulling everything together - by reducing transportation distance - while in the same time, you need to introduce some incentives for workplaces to split to sub branches.