Identify Dollar Store Brush Flaws

What happens here

Continuing with the dollar store brush, the painter observes that the brush is so stiff it doesn't allow the paint to cover 100%, leading to 'white marks underneath' and visible 'white streaks all over the place.' The filaments of the brush are noted as 'not making a nice point' and are 'splayed out,' making it impossible to achieve a sharp, clean line. This results in a messy, uneven edge that would require significant touch-ups, undermining the 'one-coat' claim of the paint and making the task 'challenging' and 'frustrating.' The painter ultimately decides to stop using it due to its poor performance.

Goal: Further use of the cheap brush reveals its inability to cover adequately, leaving streaks, and its splayed filaments preventing a sharp cutting line.