Why my feet, no matter what shoes I wear. Half of the heel is always ground flat, does anyone know if there is any way to correct it?

The analysis is correct. When walking, the foot is always turned outward, so half of the heel of the shoe is always worn flat. There may also be some foot pronation. The corrective method is to pay attention to overcoming the "eight feet"; practice cat walking, which means walking in a straight line with both feet; wear corrective shoes with valgus feet; use wide gauze leggings to correct it.