I'm not saying it doesn't show signs of a neglected area, I just think you're reading too much into certain aspects which may be explained through the area in which the picture was taken.
I'm not sure how long the building has been in that state, but I would imagine less than a year from the vegetation, but that's hard to judge if it all dies in winter. Then again, vegetation usually grows very quickly in those areas. That said, small municipalities move slower, they have less leeway in the budget to deal with unforeseen circumstances.
A lot of what you're stated seems to indicate that you see the open areas here as a sign of neglect or failure. Often in rural areas, building are much more spread out unless they are are towards the town center. There's no reason to build next to someone if you can have a lot or two between you and them. As a city expands, these are naturally filled in as sparse building pushes farther out from the town center and some people don't want to be that far out.
As for the sidewalks and concrete, areas with wet winters that continually fluctuate between freezing and non-freezing temperatures are particularly bad on brick and concrete buildings. The continual expansion of the water when it turns into ice and back into water quickly destroys concrete in these areas. Michigan is known to be particularly bad.
In truth, looking down GlenWood Ave from that picture looks fairly pleasant to me. This could easily be a few hundred feet in either of the towns my parents are from in rural Wisconsin, and much of those towns looks fairly pleasant, if extremely spread out, to my eyes.
For comparison, here's another random spot I found by just choosing a place in google maps and zooming in[1]. Every town has some run-down areas if it's old enough, but having a run-down area doesn't necessarily mean the economy is dead (but I'm not disputing that the economy is likely bad, just that the picture is more indicative of an area than a situation).
1: https://www.google.com/maps/@43.0188356,-83.6795166,3a,75y,1...