I admit to having been swayed by some of those arguments in the past, but the purely utilitarian case I feel has never been strongly made (and should be):
Are more people harmed in the process of police enforcing traffic laws (unlawful violence, egregious or excessive citation, etc.) than are harmed because of behavior enabled or exacerbated by unenforced traffic laws (running red lights, speeding, driving with lights off which result in property damage, injury, or death, or unlicensed vehicles used in other crimes, etc.).
Either way there is a social justice argument to be made, and I'm surprised I haven't heard a strong voice for enforcement, because my intuition is that more people are harmed in more broad economic terms when traffic violations are allowed to proliferate than those who would be harmed by interactions with police which run foul. It's just that when someone innocent gets unjustly murdered during a police interaction, it's such a horrific and newsworthy event and kind of distracts from regular, daily injustices (including traffic deaths). In a way kind of like mass shootings vs more regular low-grade gun violence.