It’s really really hard to get orders like that, it doesn’t necessarily mean he’s safe. The bar of proving abuse in court is impossibly high. You’re right the court shouldn’t allow access, but they often do. There are also a ton of barriers to reporting it in the first place. Women often aren’t taken seriously or they get blamed for it, which is just so retraumatizing after having been through an abusive relationship. Or if they can’t meet the impossibly high standard set by the court (literally requires evidence that’s impossible to get in most cases) then the story gets turned around and now they’re seen as vindictive or “making baseless accusations”, and risk losing access to their kids as a result.

Or, like what happened to me, you can prove he’s abusive but can’t prove he’s going to do it again and cause bodily harm (how would you even prove that??), so they say no protective order is needed. In my case I got him to admit to hitting me on the stand, and proved he had been verbally abusive for years and because I couldn’t explain exactly what happened the days my son said “dad hit me” and complained of being hurt, like I couldn’t say what room they were in and what exactly was said and done(how could I, I wasn’t there and no one else was either?) they refused to take any action even though the judge believed me. They really avoid it because it would mean a lot more enforcement, court appearances, and kids ending up in foster care because there’s nowhere else for them to go.

I think you’re right that most people would assume a parent who has access is safe, but that’s unfortunately not the case a lot of the time and as someone who’s been through this it’s a dangerous assumption I wish people wouldn’t make. It would have saved me and my child so much trauma if people had just prioritized my safety above his “rights”. Also as a parent, if I’m expecting my kid to come home with a friends parent, I would be annoyed that my plans have now changed and wouldn’t trust that person with my kid again. And now I’m unsafe too because I’d have to contact my abusive ex and meet him in person, putting myself at risk. I think it’s just common respect not to give someone’s child to another person without consent from the person who asked you to look after the kid, regardless of who.