I feel like this is the kind of advice that fits perfect when everything is going swimmingly but becomes much more complicated when other negative influencing factors come in to play.

When they are blind to something that you can plainly see is a net-negative for their life it seems like it would be much harder to not intervene.

I'm not speaking as someone who has lived this but I have observed a close family member who very much has the relationships and parenting style you're describing and I've watched this parent go through incredibly challenging situation after situation as her kids have grown into teenagehood (covid really did a number on kids coming of age). It's not that her kids are bad either, a tad naive perhaps, but genuinely good kids.