Would you use this paint brush accessory? What do you think you gain by adding it to your brush?

What happens here

This video demonstrates a unique pistol-grip handle attachment for paintbrushes, showcasing its installation and use while painting window trim with white acrylic paint. The presenter evaluates the accessory's practical application, particularly for 'cutting-in' precise lines, within the context of using synthetic-bristle brushes ideal for acrylics.