What would you say to adults who might still be living with parents or other family?

If they're in their 20's and building life experiences and stability and a savings they're really smart. If they're partying and blowing money and building nothing that's bad

It depends why they are living there, if it's just simple failure to launch then they need to get their arse into gear, stop sponging off mum and dad and take responsibility but there might be other reasons, care needs or a financial issue. Sometimes it's not always that simple.