Re: Low-voltage DC is just USB now
Not to mention that they're expensive, especially for the newer ones that support 18W charging USB PD or QC. I can purchase a 20-pack of standard mains receptacles for the price of one of those. They also tend to be a tight fit in many electrical boxes. And as you point out, the advertised power rating is usually for the unit in total, not per port.
They might be nice for hotels or guest rooms, but I wouldn't want them elsewhere.