If I had a grandkid that needed to move in with me, nothing would change on my end.That's pretty much how it used to be but as I'm sure you know it isn't much anymore. And on top of that much of our taxes go to supporting other people's kids(and adults) mistakes.
My sons hated the rules, hated the curfews, hated the getting homework done before going to play with friends, but my goal was to be a parent and not a friend.
Only one has children now, and he has the same rules with his kids that he hated to live under.
Training and leading by example works.