I think it could make a difference. A lot of devices have power factor correction (pfc) now. To draw a current without harmonics from the grid. You wouldn’t need a pfc stage anymore.

Some kind of voltage conversion would be needed anyway. Most electronic devices run at 5V, 3.3V or 1.8V. And that's limiting cable lengths to a few meters (probably less than 5m).

Yeah of course, but the pfc stage boosts the voltage first up above the ac peak voltage and then a second stage steps it down to whatever voltage is needed. If one has a dc grid one doesn’t need the pfc stage (but of course still the second stage).