You can’t demand love and respect from a child when you don’t give it in return. You actually wonder why so many siblings feel like the other is the favorite.
Also, you cannot buy a child’s love. Personally myself, I’d rather have you tell me “hey, I love you!” Then you spending $20, $30, or $50+ on me.
Like you gave me the gift of life, I don’t need anything else. If you act like a dick you’ll get it in return.