The event with the family is interesting because it poses the "Is it worth it" question in a very intimidating way.
The scene with the family was needed to serve the thematic purposes of the movie. It was the only place where we saw a family who was functioning as it should be. It was loving, caring, kind, charitable...full humanity that has been bled out from the lives of all 3 protagonists. You could argue that it's diegetic inclusion was questionable, since perhaps Charles should have known better (even though he was suffering from dementia), or that Logan should have really put his foot down. But the truth was, both Charles and Logan needed this moment, the chance to just sit down and eat a meal with other human beings who have no ulterior motives. Just, psychologically, they needed to be partake in a humane event. What sells it the most is Charles' insistence on staying the night. "Just until morning? Then we'll leave, first light." He's almost like a child, begging to stay in his happy place putting Logan in the position of being the adult who should have made the responsible decision. But he's also like a terminally ill man with a painful cancer eating away at his bones, asking that his nurse leave the morphine on just a little longer, so he can avoid pain for just a little longer.
I see both these interpretations as equally true, even if they are mutually exclusive in a way. Having dinner with the family is a luxury...but is it? Moving on may have let him continue to live a bit longer, but would it have been worth living (for them) if the last thoughts were about those people they could have made a connection with and didn't? Because to people like Charles, once you remove enough humanity, death is truly preferable.
But that's not truly the challenge this segment of the film presents. It's also the fact that their decisions have consequences for those around them. Now, Logan and Charles can't truly be held responsible, because ultimately, it's the decision of the villains to be villains and kill them. And honestly, how could they have known they'd be able to track them into this in the middle of nowhere farm. Still, they understood that their presence gave the opportunity that something would go wrong. Not even because of these villains, but just the fact that that's so utterly typical of their lives as a whole. And the film doesn't shy away from this. The father's final action, before finally dropping dead, is to look to logan, aim his gun, and pull the trigger. Gun wasn't loaded, but the meaning was clear. "I blame you for this" is what he said.
I feel it's perfectly valid to argue that it's 100% worth it for Charles to have stayed and gotten his last taste of human connection before he was killed, and if it was his risk alone he was taking, then it would be the right choice. But it's not him alone. His need for that moment, those feelings, that destroyed the person he was connected to. Personally speaking, as a depressed person, I find that really relatable. I'm not a movie character, so logically speaking, I know for a fact that I am not a poison onto the lives of the people I connect with, but depression can make you feel that is the case. It's pretty horrible. It makes you feel guilty just for wanting to feel human, for allowing yourself that one bit of relief from the general shittiness of your life. It makes happiness itself into a sin and conveys that numbness and misery and emotional distances are what you should feel in life. And that's bullshit, or even if it's not, it should be. But what happens when you really, truly are a poison on the lives of others? What are you supposed to do when you really do ruin others lives just by existing in their proximity? That's the reality Logan lives in, and why the whole "Daddy" line at the end is earned. Laura and the other kids are the few who benefited from Logan being in their lives.
It's a situation without an easy answer, and I don't have one to offer. Sure, they could have kept driving and the family could have lived, and even Charles might have lived longer as well. But they can't, they actually psychologically can't, live like that and not want to die.