Anecdata around SV: I've seen an uptick in urban night drivers with only their DRLs and no tail lights.

That's not true for my vehicle, I've checked.

Not sure why people are not believing you. I have a Volvo and the headlights and taillights are illuminated at all times, even when the headlight switch is "off."

The only thing that turning the headlights "on" does differently is enable high beams.

Thanks - I'm ok with that. As also mentioned, I'm NOT when it's a dark car at night with ONLY DRL and no rear lights at all - which I've seen a LOT of lately..