we had a similar situation and we started doing the family do dots system and hard lined the schedules for everyone. It was a couple of weeks of pulling teeth but now everyone is in a routine and bed time is soooo much better. It’s easier said than done, but kids want structure and need to be led by the hand until they start building their own habits. I’d say our kids still go to bed a little later than their friends that I know of, but it’s in bed every night by 9:30, limited screen time, all screens off at 8:30, etc. We’re not perfect but things are way smoother now.