Diagnosis
This is a classic symptom of restricted airflow. The motor is working, but it's struggling to pull air through. The primary suspect is, yet again, the rear filter being clogged with a fine layer of lint that's not immediately visible.
How to Fix It
Do a proper wet clean of the filter. Just tapping it isn't enough for this. Rinse it under a cold tap, rubbing the mesh gently with your fingers until the water runs clear with no grey tint. Let it air dry for a full 24 hours—any dampness will increase air resistance. While it's off, also vacuum the intake grilles on the handle.
If That Didn't Work
Check the attachment you're using. Make sure the concentrator or diffuser is clicked on securely. A poor seal where the attachment meets the dryer body can cause air to leak, reducing directed airflow. Try it without any attachment to see if the raw airflow feels stronger.
Heads Up
Power can feel subjectively lower over time. For a real test, hold the dryer about a foot from your hand on the high setting. You should feel a strong, focused stream of air, not a diffuse breeze. If it's weak even with a clean filter and no attachment, the motor may be degrading.