>

Unless they were also drunk or otherwise breaking the law.
Most people who run from hit and runs do so because they're going to eat a worse charge if they stay.
In most jurisdictions if you are driving drunk or with drugs in your car, the objectively better thing to do for your own self benefit is to go home, sober up and/or get rid of whatever illegal shit was in your car and then turn yourself in the next day or just wait for them to figure out it was you. The long-term penalties and consequences for leaving the scene of a fatal accident tend to be less severe than being confirmed to be impaired during that accident. Our laws basically incentivize people not to stop
Okay, but what about the fact that the first dude in the pickup hit a person on the interstate and then didn’t bother to pull over…? >

Which is SO stupid. They never would have caught a charge if they stopped. No jurisdiction is going to hold you responsible for running into a drunk on the interstate at night, not if you were within your lane. Even if you were speeding. As long as you STOP.