Look, these are the things that'll happen when the empire's economy starts falling down:
1) A lot of people in the various urban centers of the empire are now making less money.
2) As a consequence, they can't buy goods and services and pay taxes like they used to.
3)a) The poor people in the cities who provided them service now have no money to buy essentials.
3)b) The people in the country who sold food, wood, metal and other such materials are now selling a fair lot less of all of it. They aren't starving but they aren't doing amazing.
3)c) The governments, local, provincial and Imperial is now collecting less taxes, which means they'll cut the budget. This budget is not always very well allocated but one of the important expenses which may get cut because it can't be afforded as much anymore is the military.
4) The people in the country who used to be merely 'not amazing' are now 'literally being killed', because they are the ones feeling the military budget cuts.