I have three younger siblings. From my early 20s my dad was very vocal about me needing to move out soon - in the end I moved out when I was 25 into a rented flat with my partner. I thought that was quite late, but I didn't leave uni until 22, and had a very low salary for the first years of my working life. But my parents did make my life very uncomfortable as they wanted me to leave.
My sister on the other hand is 30 and still lives with my parents. She is on £40k (which is more than I am now!) and pays only £100 towards bills and food. She does spend about 40-50% of her time at her boyfriend's flat, but she said she doesn't want to move in there as she doesn't want to pay towards bills. She goes on about 5 holidays a year, which includes luxurious destinations such as the Caribbean, Bali etc. she doesn't seem to be saving to move out, In fact she's getting her bedroom redecorated.
AIBU to feel a bit bitter at the unequal attitudes from parents, and think she's a spoilt brat?