If we replaced some of those with roundabouts, others with over/underpasses

That’s definitely another approach, although these kinds of infrastructure changes are expensive and come with their own risks. Roundabouts take up more space than four-way stops, while underpasses flood and overpasses freeze. Your essential problem - moving too many overlarge vehicles through too small a space - is mitigated, but not resolved.

But yes, a camera that functions as a revenue stream is far more attractive than anything that might actually save lives.