"Because many modern devices operate internally on direct current (DC)"
But notably the high power consumers like electrical stove, air conditioning, washing machines etc. do not. And it's not that with DC throughout there are no conversions. Solar cells' output varies greatly, hence it needs to be DC/DC converted to a fix voltage to be of any use. The same, albeit to a much lesser extend, applies to batteries. Further, there is no one single voltage, AC or DC, which is optimal for all uses. Even for devices which receive DC voltage, e.g. laptops, there are internal DC/DC converters.
Removing the AC/DC conversion seems hardly worth the trouble. High efficiency AC/DC converters can be constructed. It's rather a question on how much one is willing to spend on such.
Removing the AC/DC conversion seems hardly worth the trouble. High efficiency AC/DC converters can be constructed. It's rather a question on how much one is willing to spend on such.