One of the inspirations for this idea is the street-level view in a city simulator game -- Cities: Skylines. The sim-citizens there all have homes, go to work, come home, use the subway, and so on. Businesses need deliveries of goods and generate truck traffic. Trains run and people use them; same for buses and subways. It gets traffic jams, and people complain. Police and fire have to respond to emergencies, and big things like forest fires and floods can make a mess. Typical tropes for city sim games -- but also a very nice fit for a superhero game.
All the things that can go wrong and how a hero (of various kinds and levels) could help out, or how a villains could take advantage of it -- create a huge traffic jam and then rob the bank! Easier getaway with your loot since PPD can't get there fast enough! Your infamy soars! The simulation creates city-consequences from the villain's actions -- ones that other players can be involved with.
Or there's a Rikti attack on Atlas Park; high level heroes respond and down a dropship! But it crashes into a building and creates street-level mayhem. Several city systems are compromised, and the simulation presents opportunities for other heroes to mitigate those effects and help restoring things to normal the next day.
Remember the Troll rave in Skyway? Imagine if that could happen almost anywhere, and it was linked to actual movement of troll gang members who could be interdicted. Imagine if the mayhem they create affects other citizens in the area. Imagine this happens in an area that's under control of some other gang -- the simulation systems could generate a trolls vs Lost gang war over it.
It would take a lot of design and implementation work to get the simulation to be generally stable, and resilient to the adverse actions of players. Maybe the more ambitious concepts won't work, and all you can do is have pedestrian and vehicle traffic be entity based and sort of make sense. I'd still count that a win.
Looking back to the design period for CoH back before 2004, there wasn't the tech, computing power, or even the need for a new MMO offering to have this deep a simulation behind it in order to be successful; and there was even the simulated ecology disaster from that other game to argue against subtle, perhaps even over-complicated, supporting systems. But it's almost 20 years later, and I think we can demand more from our games today.