All those modern lightweight wall warts are switching DCDC converters anyway—they just have a rectifier and capacitor on the front end to get an approximate DC

All those modern lightweight wall warts are switching DCDC converters anyway—they just have a rectifier and capacitor on the front end to get an approximate DC waveform to start from. That's also why modern power supplies are almost always universal for 240@50Hz or 120@60Hz. The frequency is irrelevant and the DCDC can adapt to a huge range of input voltages because the ratio isn't locked in by the wiring in a transformer. Modern power electronics are not just more flexible, smaller, and lighter, they're more efficient as well.