Dynamic topology in blender 2.81a is different from the current version. Sculpting certain areas of the bird are now more difficult.

ssaki2006 Dyntopo has definitely changed a key thing since this video was recorded: The detail size values. When this was recorded I typically started at 30 px for basic shape sculpting, then 20 px for mid-level sculpting, then 10 px for details.

With current Blender I generally use 10 px, 7 px, and 5 px respectively. Try that and the experience should be much more similar.