The answer to 'why is my vacuum neglected' is that a neglected vacuum can be caused by a variety of factors, including not changing the filter or bag regularly, not emptying the canister often enough, and not performing basic maintenance. Symptoms of a neglected vacuum include reduced suction power, clogged filters, and poor cleaning performance.
To address a neglected vacuum, start by checking the filter and bag - replace them if they are dirty or clogged. Empty the canister regularly and check for any clogs or obstructions in the hose or brush. You may also need to clean the vacuum's interior and exterior to remove built-up dust and debris. If these basic maintenance steps don't resolve the issue, it may be time to call a professional vacuum repair technician to diagnose and fix any deeper problems.