> They also cite things like cars getting bigger, but frankly even cars from the 50s going at even moderate speeds can be deadly, so where’s the actual connection?

There has been a lot of study of this particular issue, linking larger cars both to disproportionately high rates of pedestrian crashes and do higher fatality rates in the crashes that happen. Here is some research from IIHS, for example. I don't think this is a particularly controversial empirical point. Of course any car can be deadly, but taller, heavier, faster cars are more likely to be deadly (one of the things that is likely to be harmful about the EV revolution), and larger vehicles have more visibility limitations than smaller ones.

Anecdotally, if you look back through the pedestrian & cyclist deaths in DC, I think you will see "large vehicle turns into a pedestrian or cyclist" is probably the biggest recurring theme.