The answer to 'why is my vacuum dusty' is that a dirty or clogged vacuum can cause dust and debris to be blown back into the air instead of being properly captured. Common causes include a full dust bag, blocked filters, or a damaged or worn-out vacuum hose. This can lead to reduced suction power and poor cleaning performance.
To fix a dusty vacuum, start by checking the dust bag or canister and replacing it if it's full. Next, inspect the filters and clean or replace them according to the manufacturer's instructions. You should also check the vacuum hose for any clogs or damage, and clear any blockages. If the issue persists, it may be time to have the vacuum serviced by a professional to ensure it's working properly.