But these are sometimes making it safer for the occupants at the expense of the rest of the environment (think smaller windows and fatter A pillars making children harder to see, or strengthened soundproofing making children harder to hear.)

I don't think this is a very good argument... I want my car to be as quiet as possible, on terms of the noise it makes and it's soundproofness. That making people harder to hear outside is irrelevant, as I mainly use my eyes to scan the environment for people, not my ears.

Also I think we've done enough damage to the world with the (British accent) "what about the children" arguments...

I think this one in particular ticks me off personally because people I meet are all moralistic about me listening to podcasts while bicycling in traffic, telling me I "shouldn't block the sounds of the environment."

And I'm left wondering: have these people ever been in a modern car? Just sitting in it blocks out more of the environment than my open-backed earbuds. If I can drive one of those without causing an accident, surely I can listen to podcasts on my (much slower) bicycle without causing an accident too!

Isn't that advice about your own safety?

I see it now where people bellyache about headphones and runners and don't really get it. I don't have the volume jacked up and I know where to look for traffic.

On a bike I don't want headphones just because I'm mixing with so much more traffic and want that awareness.

But are children harder to see than from older cars? It isn't like the windows were huge nor the beams small.

Are children really harder to hear? Old cars were louder. How much sound did they cover up just with noise? How much more could you hear in an old car compared to a modern electric car?