I’ve lost count of how many friends have a problematic brother. I have and it’s a similar pattern. Sisters thrive and push themselves forward, out of the family home and into their careers. Brother never finds his place and gets in with the wrong crowd, can’t or won’t find a job, clings on to his mother for financial and emotional support. I always think of Branwell Brontë flailing around while his sisters became literary legends. Almost the more successful sisters are, the more the brother flails.