I’m a dog with a bone on this subject. See this thread: IEEE P2030.10 standard for DC Micro grids for Rural and Remote Electricity Access Applications
Most electronic devices run on low voltage DC and so if you connect these devices to a battery they will work 100%.
The other issue is the efficiency of using DC over AC. The IEEE webinar explains how DC grids will make an appearance especially in poor countries that don’t have a national grid.
No matter what, we will see DC as a standard power source emerging (at different voltages to cater for the specific power requirements)