Mostly on board with not assimilating townships, but it's a little bit the other way around with tax revenue. It's extremely expensive to provide municipal services to suburban and rural customers. Cities, with their much better tax revenue per acre, tend to subsidize rural customers.

Consider sewer, water, electricity, roads. All that extra pipe and wire to service a whole bunch of spread-out residences is quite expensive, and the revenue obtained from those residences is small. Which is why you have all these little towns going bankrupt, because their finances don't make sense.

I am on board with towns being able to manage their own affairs, but unsustainable development without the tax base to support it is causing a LOT of trouble. They spend without taxing.

edit: I see other people made this point better than I did.