At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga.
Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus.
Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.
The fall of the Western Empire wrecked a lot of institutions that were relatively commonplace under one, unified government. Schools, a central army, a sophisticated bureaucracy, and public works such as aqueducts, roads, etc.. all fell into disrepair and collapse mainly because the new "barbarian" rulers were more concerned with survival, seizing wealth, holding onto what they had gained, and in competing with each other than in educating their people or spending their loot in building or maintaining massive new monuments and buildings. It was one of the reasons why it was called the Dark Ages, though Rome's collapse had also opened the way for other new nations to rise up in Europe to eventually attempt to mirror and replace it.
On the other hand, the Roman Catholic Church became a repository of preserved knowledge as a result, though for most everyone else out in the post-apocalyptic decay of the empire's fall, that was little consolation when they were caught between warring factions, raiders, and natural dangers. It's also one of the reasons why the Eastern Empire maintained its power for nearly a thousand years after Rome's fall as it didn't face the same problems, was much closer to wealthier trade routes to bring it wealth and goods, and was controlled by a strong central government inheriting what the Western Empire had lost.