It's impossible to come up with a single solution that fits every situation. As nice as it would be, it's impossible. There are situations where distance is a positive. So much depends on the individuals involved - parents and children alike.
Personally, I don't think Nic Sheff is someone to be considered a poster child in favor of abolishing move-aways. Yes, an argument could likely be made that if his mother hadn't moved so far away, he'd never have ended up addicted to meth. But a lot of people end up addicted to a lot of different stuff with two parents living together in one home, too.
Yes, my kids deal with long-distance parenting. It has, for them, been more positive than not. I think. I won't/can't go into details. One has an excellent relationship with Dad, the other not so much. But... I think proximity would have ruined both irreparably.
Sometimes, parents have to do the best they can.